Yanmar 4TNE92-NMH, 4TNE92-NMHA, 4TNE98-NMH Service Manual

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com/
TNE series
SERVICE MANUAL
4TNE92-NMH • 4TNE92-NMHA
4TNE98-NMH
TNE Service Manual
P/N: 0B2991-U0001
INDUSTRIAL
ENGINES
UTILEV PN: 76000368
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English Language Manual Available

If you would like a copy of this manual in the English language, please contact your local authorized Yanmar
industrial engine dealer or distributor. A list of authorized Yanmar industrial engine dealers and distributors
can be found at http://www.yanmar.co.jp/english/index-network.htm. Note that authorized Yanmar
industrial engine dealers and distributors are indicated as “Land” under the “Sales Network” menu.
Disclaimers:
We reserve the right to change specifications and to improve our products without notice or obligation.
Yanmar and are registered trademarks of Yanmar Co., Ltd. in Japan, the United States and / or
other countries.
All Rights Reserved:
No part of this publication may be reproduced or used in any form by any means - graphic, electronic, or
mechanical, including photocopying, recording, taping, or information storage and retrieval systems - without
the written permission of Yanmar Co., Ltd.
© 2005 Yanmar Co. Ltd.
ii TNE Service Manual

TABLE OF
CONTENTS
TNE Service Manual
Introduction ............................................................................................ 1-1
Yanmar Warranties ............................................................................... 2-1
Safety .................................................................................................... 3-1
General Service Information .................................................................. 4-1
Periodic Maintenance ............................................................................ 5-1
Engine ................................................................................................... 6-1
Fuel System .......................................................................................... 7-1
Cooling System ..................................................................................... 8-1
Lubrication System ................................................................................ 9-1
Starter Motor ....................................................................................... 10-1
Alternator ............................................................................................. 11-1
Electric Wiring ..................................................................................... 12-1
Troubleshooting ................................................................................... 13-1
TNE Service Manual iii

This Page Intentionally Left Blank
iv TNE Service Manual

Section 1
INTRODUCTION
TNE Service Manual
This manual describes the service procedures for
the TNE series indirect injection engines. These
engines are certified by the U.S. EPA, California
ARB and/or the 97/68/EC Directive for industrial
use.
Please use this manual for accurate, quick and safe
servicing of the engine. Since the directions in this
manual are for a typical engine, some
specifications and components may be different
from your engine. Refer to the documentation
supplied by the optional equipment manufacturer
for specific service instructions.
Yanmar products are continuously undergoing
improvement. This Service Manual might not
address possible field modifications to the
equipment. Contact an authorized Yanmar
industrial engine dealer or distributor for answers to
any questions relating to field modifications.
TNE Service Manual 1-1

INTRODUCTION
1-2 TNE Service Manual

Section 2
YANMAR
WARRANTIES
TNE Service Manual
Table of Contents
Page
Yanmar Limited Warranty................................................................ 2-3
What is Covered by this Warranty? ........................................... 2-3
How Long is the Warranty Period?............................................ 2-3
What the Engine Owner Must Do: ............................................. 2-3
To Locate an Authorized Yanmar Industrial Engine
Dealer or Distributor: ................................................................. 2-3
What Yanmar Will Do: ............................................................... 2-3
What is Not Covered by this Warranty? .................................... 2-4
Warranty Limitations:................................................................. 2-4
Warranty Modifications: ............................................................. 2-4
Questions: ................................................................................. 2-4
Customer Registration............................................................... 2-4
Yanmar Co., Ltd. Limited Emission Control
System Warranty - USA Only.......................................................... 2-5
Your Warranty Rights and Obligations: ..................................... 2-5
Manufacturer’s Warranty Period:............................................... 2-5
Warranty Coverage: .................................................................. 2-6
Warranted Parts: ....................................................................... 2-6
Exclusions: ................................................................................ 2-7
Owner’s Warranty Responsibilities:........................................... 2-7

YANMAR WARRANTIES

YANMAR WARRANTIES
YANMAR LIMITED WARRANTY

What is Covered by this Warranty?
Yanmar warrants to the original retail purchaser that your new Yanmar TNE Series Industrial Engine will be
free from defects in material and / or workmanship for the duration of the warranty period.
How Long is the Warranty Period?

The Yanmar standard limited warranty period begins on the date of the delivery of the new Yanmar TNE
Series Industrial Engine to the first retail purchaser and extends for a period of twenty-four (24) months or
two-thousand (2000) engine operation hours, whichever occurs first.
What the Engine Owner Must Do:

If you believe your Yanmar engine has experienced a failure due to a defect in material and / or
workmanship, you must contact an authorized Yanmar industrial engine dealer or distributor within thirty (30)
days of discovering the failure. You must provide proof of ownership of the engine, proof of the date of the
engine purchase and delivery, and documentation of the engine operation hours. You are responsible for the
transportation of the engine to and from the repair location as designated by Yanmar.
Yanmar strongly recommends you register your engine as soon as possible after purchase in order to
facilitate any future warranty matters.
To Locate an Authorized Yanmar Industrial Engine Dealer or Distributor:

You can locate your nearest authorized Yanmar industrial engine dealer or distributor by visiting the Yanmar
Corp., Ltd. web site at:
http://www.yanmar.co.jp
• The Japanese language page will be displayed. For English language “click” on “English Page.”
• “Click” on “Network” in the web site heading to view the “Yanmar Worldwide Network.”
• Choose and “Click” on the desired product group.
• “Click” on the Icon closest to your region.
• “Click” on the disired country or Associate company to locate your nearest authorized Yanmar industrial
engine dealer or distributor.
• You may also contact Yanmar by clicking on “Inquiry” in the web site heading.
What Yanmar Will Do:

Yanmar warrants to the original retail purchaser of a new Yanmar engine that Yanmar will make such repairs
and / or replacements necessary to correct any defects in materials and / or workmanship discovered during
the warranty period. Such repairs and / or replacements will be made at a location designated by Yanmar.

YANMAR WARRANTIES
Yanmar Limited Warranty - Continued
What is Not Covered by this Warranty?

This Warranty does not cover parts affected by or damaged by, but not limited to, accident, misuse, abuse,
“Acts of God,” neglect, improper installation, improper maintenance, improper storage, the use of unsuitable
attachments or parts, the use of contaminated fuels, the use of fuels, oils, lubricants, or fluids other than
those recommended in your Yanmar Operation Manual, unauthorized alterations or modifications, ordinary
wear and tear, and rust or corrosion. This Warranty does not cover the cost of parts and / or labor required to
perform normal / scheduled maintenance on your Yanmar engine. This Warranty does not cover consumable
parts such as, but not limited to filters, belts, hoses, fuel injector nozzles, lubricants and cleaning fluids.
Warranty Limitations:
The foregoing is Yanmar's only obligation to you and your exclusive remedy for breach of warranty.
Failure to follow the requirements for submitting a claim under this Warranty may result in a waiver of all
claims for damages and other relief. In no event shall Yanmar or any authorized industrial engine dealer
or distributor be liable for incidental, special or consequential damages. Such consequential damages
may include, but not be limited to, loss of revenue, loan payments, cost of rental of substitute equipment,
insurance coverage, storage, lodging, transportation, fuel, mileage and telephone costs. The limitations in
this Warranty apply regardless of whether your claims are based on breach of contract, tort (including
negligence and strict liability) or any other theory. Any action arising hereunder must be brought within one
(1) year after the cause of action accrues or it shall be barred. Some states and countries do not allow
certain limitations on warranties or for breach of warranties. This Warranty gives you specific legal rights,
and you may also have other rights which vary from state to state and country to country. Limitations
set forth in this paragraph shall not apply to the extent that they are prohibited by law.
Warranty Modifications:
Except as modified in writing and signed by the parties, this Warranty is and shall remain the complete and
exclusive agreement between the parties with respect to warranties, superseding all prior agreements,
written and oral, and all other communications between the parties relating to warranties. No person or
entity is authorized to give any other warranty or to assume any other obligation on behalf of
Yanmar, either orally or in writing.
Questions:
If you have any questions or concerns regarding this Warranty, please call or write to the nearest authorized
Yanmar industrial engine dealer or distributor or other authorized facility.
Customer Registration
Customer registration is very important for the original retail purchaser to enable Yanmar to provide
the best support for your engine.
At the time of purchase, Yanmar highly recommends registering the customer’s information through website
http://www.yanmar.co.jp as soon as possible.
If it is not possible to access the website, please contact the nearest authorized Yanmar industrial engine
dealer or distributor.

YANMAR WARRANTIES
YANMAR CO., LTD. LIMITED EMISSION CONTROL SYSTEM

WARRANTY - USA ONLY
Your Warranty Rights and Obligations:
California
The California Air Resources Board (CARB) then Environmental Protection Agency (EPA) and Yanmar Co.,
Ltd. hereafter referred to as Yanmar, are pleased to explain the emission control system warranty on your
industrial compression-ignition engine. In California, model year 2000 or later off-road compression-ignition
engines must be designed, built and equipped to meet the State’s stringent anti-smog standards. In all
states, 1998 and later non-road compression-ignition engines must be designed, built and equipped to meet
the United States EPA emissions standards. Yanmar warrants the emission control system on your engine
for the periods of time listed below provided there has been no abuse, neglect or improper maintenance of
your engine.
Your emission control system may include parts such as the fuel injection system and the air induction
system. Also included may be hoses, belts, connectors and other emission-related assemblies.
Where a warrantable condition exists, Yanmar will repair your non-road compression-ignition engine at no
charge to you including diagnosis, parts and labor.
Manufacturer’s Warranty Period:

The model year 1998 or later certified and labeled non-road compression-ignition engines are warranted for
the periods listed below. If any emission-related part on your engine is found to be defective during the
applicable warranty period, the part will be replaced by Yanmar.
Engine Type Warranty Period by Number of Years or Hours of Operation

Constant speed engines rated at or above Warranty period is five (5) years or 3,000 hours of use, whichever occurs first. In
50 hp (37 kW) the absence of a device to measure hours of use, the engine has a warranty
period of five (5) years.
Constant speed engines rated under 50 hp Warranty period is two (2) years or 3,000 hours of use, whichever occurs first. In
SAE (37 kW) with rated speeds greater than the absence of a device to measure hours of use, the engine has a warranty
or equal to 3,000 rpm period of two (2) years.
Engines rated at or above 26 hp (19 kW) Warranty period is five (5) years or 3,000 hours of use, whichever occurs first. In
the absence of a device to measure hours of use, the engine has a warranty
period of five (5) years.
Engines rated under 26 hp (19 kW) Warranty period is two (2) years or 3,000 hours of use, whichever occurs first. In
the absence of a device to measure hours of use, the engine has a warranty
period of two (2) years.

YANMAR WARRANTIES
Limited Emission Control System Warranty - USA Only - Continued
Warranty Coverage:
This warranty is transferable to each subsequent purchaser for the duration of the warranty period. Repair or
replacement of any warranted part will be performed at an authorized Yanmar dealer.
Warranted parts not scheduled for replacement as required maintenance in the Operation Manual shall be
warranted for the warranty period. Warranted parts scheduled for replacement as required maintenance in
the owner’s manual are warranted for the period of time prior to the first scheduled replacement. Any part
repaired or replaced under warranty shall be warranted for the remaining warranty period.
During the warranty period, Yanmar is liable for damages to other engine components caused by the failure
of any warranted part during the warranty period.
Any replacement part which is functionally identical to the original equipment part in all respects may be
used in the maintenance or repair of your engine, and shall not reduce Yanmar’s warranty obligations.
Add-on or modified parts that are not exempted may not be used. The use of any non-exempted add-on or
modified parts shall be grounds for disallowing a warranty.
Warranted Parts:
This warranty covers engine components that are a part of the emission control system of the engine as
delivered by Yanmar to the original retail purchaser. Such components may include the following:
• Fuel Injection System
• Cold Start Enrichment System
• Intake Manifold
• Turbocharger Systems
• Exhaust Manifold
• Positive Crankcase Ventilation System
• Hoses, belts, connectors and assemblies associated with emission control systems
Since emissions related parts may vary slightly between models, certain models may not contain all of these
parts and other models may contain the functional equivalents.

YANMAR WARRANTIES
Limited Emission Control System Warranty - USA Only - Continued
Exclusions: Owner’s Warranty Responsibilities:

Failures other than those arising from defects in As the engine owner, you are responsible for
material and / or workmanship are not covered by the performance of the required maintenance
this warranty. The warranty does not extend to the listed in your owner’s manual. Yanmar
following: malfunctions caused by abuse, misuse, recommends that you retain all documentation,
improper adjustment, modification, alteration, including receipts, covering maintenance on your
tampering, disconnection, improper or inadequate non-road compression-ignition engine, but Yanmar
maintenance or use of non-recommended fuels cannot deny warranty solely for the lack of receipts,
and lubricating oils; accident-caused damage, and or for your failure to ensure the performance of all
replacement of expendable items made in scheduled maintenance.
connection with scheduled maintenance. Yanmar
disclaims any responsibility for incidental or Yanmar may deny your warranty coverage of your
consequential damages such as loss of time, non-road compression-ignition engine or a part has
inconvenience, loss of use of equipment / engine or failed due to abuse, neglect, improper maintenance
commercial loss. or unapproved modifications.
Your engine is designed to operate on diesel fuel
only. Use of any other fuel may result in your engine
no longer operating in compliance with applicable
emissions requirements.
You are responsible for initiating the warranty
process. You must present your engine to a Yanmar
dealer as soon as a problem exists. The warranty
repairs should be completed by the dealer as
expeditiously as possible. If you have any questions
regarding your warranty rights and responsibilities,
or would like information on the nearest Yanmar
dealer or authorized service center, you should
contact Yanmar America Corporation at
1-800-872-2867.

YANMAR WARRANTIES

Section 3
SAFETY
TNE Service Manual
SAFETY STATEMENTS
A WARNING
Yanmar is concerned for your safety and your Warning (the word “WARNING” is in
machine’s condition. Safety statements are one of black letters with an orange rectangle
the primary ways to call your attention to the behind it) – indicates a potentially
potential hazards associated with Yanmar TNE hazardous situation which, if not
engine operation. Follow the precautions listed avoided, could result in death or serious
throughout the manual before operation, during injury.
operation and during periodic maintenance
0000001en
procedures for your safety, the safety of others and
to protect the performance of your engine. Keep the
labels from becoming dirty or torn and replace A CAUTION
them if they are lost or damaged. Also, if you need Caution (the word “CAUTION” is in black
to replace a part that has a label attached to it, letters with a yellow rectangle behind it)
make sure you order the new part and label at the – indicates a potentially hazardous
same time. situation which, if not avoided, may
result in minor or moderate injury.
This safety alert symbol appears with
A
0000001en
most safety statements. It means
attention, become alert, your safety is
involved! Please read and abide by the CAUTION
message that follows the safety alert Caution without the safety alert symbol
symbol. indicates a potentially hazardous
situation that can cause damage to the
A DANGER machine, personal property and / or the
Danger (the word “DANGER” is in white environment or cause the machine to
letters with a red rectangle behind it) – operate improperly.
indicates an imminently hazardous 0000001en
situation which, if not avoided, will

result in death or serious injury. Danger
is limited to the most extreme
situations.
0000001en

SAFETY
SAFETY PRECAUTIONS During Operation and Maintenance
Before You Operate A DANGER

CAUTION
SCALD HAZARD!
• NEVER remove the radiator cap if the
NEVER permit anyone to operate the
engine is hot. Steam and hot engine
engine or driven machine without proper coolant will spurt out and seriously
training. burn you. Allow the engine to cool
• Read and understand this Operation down before you attempt to remove
Manual before you operate the the radiator cap.
machine to ensure that you follow safe
• Securely tighten the radiator cap after
operating practices and maintenance you check the radiator. Steam can
procedures. spurt out during engine operation if
• Machine safety signs and labels are the cap is loose.
additional reminders for safe operating
• ALWAYS check the level of engine
and maintenance techniques. coolant by observing the reserve tank.
• See your authorized Yanmar industrial • Failure to comply will result in death or
engine dealer or distributor for serious injury.
additional training.
0000002en
0000002en
A DANGER
EXPLOSION HAZARD!
• Keep the area around the battery well
ventilated. While the engine is running
or the battery is charging, hydrogen
gas is produced which can be easily
ignited.
• Keep sparks, open flame and any other
form of ignition away.
• Failure to comply will result in death or
serious injury.
0000003en

SAFETY
A DANGER A DANGER
FIRE AND EXPLOSION HAZARD! FIRE AND EXPLOSION HAZARD!

• Diesel fuel is extremely flammable and • Diesel fuel is extremely flammable and
explosive under certain conditions. explosive under certain conditions.
• When you remove any fuel system • NEVER remove the fuel cap with
component to perform maintenance engine running.
(such as changing the fuel filter) place • Failure to comply will result in death or
an approved container under the serious injury.
opening to catch the fuel.
0000011en
• NEVER use a shop rag to catch the
fuel. Vapors from the rag are extremely
flammable and explosive.
• Wipe up any spills immediately.
• Wear eye protection. The fuel system
is under pressure and fuel could spray
out when you remove any fuel system
component.
serious injury.
0000009en
A DANGER
FIRE AND EXPLOSION HAZARD!

• Diesel fuel is extremely flammable and
explosive under certain conditions.
• NEVER use diesel fuel as a cleaning
agent.
serious injury.
0000012en

SAFETY
A DANGER A DANGER

• Diesel fuel is extremely flammable and • Only use the key switch to start the
explosive under certain conditions. engine.
• Place an approved container under the • NEVER jump start the engine. Sparks
air bleed port when you prime the fuel caused by jumping the battery to the
system. Never use a shop rag to catch starter terminals may cause a fire or
the fuel. Wipe up any spills explosion.
immediately. ALWAYS close the air
bleed port after you complete priming
serious injury.
the system.
0000004en
• Wear eye protection. The fuel system 0

out when you open the air bleed port. A DANGER
• If the unit has an electric fuel pump,
turn the key switch to the ON position
for 10 to 15 seconds, or until the fuel
coming out of the air bleed port is free
of bubbles, to allow the electric fuel FIRE AND EXPLOSION HAZARD!
pump to prime the system. • Diesel fuel is extremely flammable and
• If the unit has a mechanical fuel pump, explosive under certain conditions.
operate the fuel priming pump several • Only fill fuel tank with diesel fuel.
times until the fuel coming out of the Filling fuel tank with gasoline may
air bleed port is free of bubbles. result in a fire.
• Failure to comply will result in death or • NEVER refuel with engine running.
serious injury.
0000006en
• Wipe up all spills immediately.
• Keep sparks, open flames or any other
form of ignition (match, cigarette,
static electric source) away when
fueling / refueling.
• NEVER overfill the fuel tank.
• Fill fuel tank and store fuel in a
well-ventilated area only.
serious injury.
0000005en

SAFETY
0
A DANGER A DANGER

• Diesel fuel is extremely flammable and CRUSH HAZARD!
explosive under certain conditions. • When you need to transport an engine
• Before you operate the engine, check for repair have a helper assist you
for fuel leaks. Replace rubberized fuel attach it to a hoist and load it on a
hoses every two years or every 2000 truck.
hours of engine operation, whichever • NEVER stand under hoisted engine. If
comes first, even if the engine has the hoist mechanism fails, the engine
been out of service. Rubberized fuel will fall on you, causing serious injury
lines tend to dry out and become or death.
brittle after two years or 2000 hours of • Failure to comply will result in death or
engine operation, whichever comes serious injury.
first.
0000008en
serious injury.
0000015en
A DANGER
EXPLOSION HAZARD!
• NEVER check the remaining battery
charge by shorting out the terminals.
This will result in a spark and may
cause an explosion or fire. Use a
hydrometer to check the remaining
battery charge.
• If the electrolyte is frozen, slowly warm
the battery before you recharge it.
serious injury.
0000007en

SAFETY
A WARNING A WARNING
SEVER HAZARD! EXHAUST HAZARD!

• Keep hands and other body parts • NEVER operate the engine in an
away from moving / rotating parts enclosed area such as a garage,
such as the cooling fan, flywheel or tunnel, underground room, manhole or
PTO shaft. ship’s hold without proper ventilation.
• Wear tight fitting clothing and keep • NEVER block windows, vents, or other
your hair short or tie it back while the means of ventilation if the engine is
engine is running. operating in an enclosed area. All
• Remove all jewelry before you operate internal combustion engines create
or service the machine. carbon monoxide gas during
operation. Accumulation of this gas
• NEVER start the engine in gear. within an enclosure could cause
Sudden movement of the engine illness or even death.
and / or machine could cause death or
serious personal injury. • Make sure that all connections are
tightened to specifications after repair
• NEVER operate the engine without the is made to the exhaust system.
guards in place.
• Failure to comply could result in death
• Before you start the engine make sure or serious injury.
that all bystanders are clear of the 0000003en
area.
• Keep children and pets away while the
engine is operating.
A WARNING
• Check before starting the engine that
any tools or shop rags used during
maintenance have been removed from
the area.
ALCOHOL AND DRUG HAZARD!
or serious injury.
0000002en
• NEVER operate the engine while you
are under the influence of alcohol or
drugs.
• NEVER operate the engine when you
are feeling ill.
or serious injury.
0000004en

SAFETY
A WARNING A WARNING
BURN HAZARD!
EXPOSURE HAZARD! • Batteries contain sulfuric acid. NEVER
• Wear personal protective equipment allow battery fluid to come in contact
such as gloves, work shoes, eye and with clothing, skin or eyes. Severe
hearing protection as required by the burns could result. ALWAYS wear
task at hand. safety goggles and protective clothing
when servicing the battery. If contact
• NEVER wear jewelry, unbuttoned
with the skin and / or eyes should
cuffs, ties or loose fitting clothing
occur, flush with a large amount of
when you are working near
water and obtain prompt medical
moving / rotating parts such as the
treatment.
cooling fan, flywheel or PTO shaft.
• ALWAYS tie long hair back when you
or serious injury.
are working near moving / rotating
0000007en
parts such as a cooling fan, flywheel,
or PTO shaft.
• NEVER operate the engine while A WARNING
wearing a headset to listen to music or
radio because it will be difficult to hear
warning signals.
or serious injury. HIGH PRESSURE HAZARD!
0000005en • Avoid skin contact with high pressure
diesel fuel spray caused by a fuel
system leak such as a broken fuel
injection line. High pressure fuel can
penetrate your skin and result in
serious injury. If you are exposed to
high pressure fuel spray obtain
prompt medical treatment.
• NEVER check for a fuel leak with your
hands. ALWAYS use a piece of wood
or cardboard. Have your authorized
Yanmar industrial engine dealer or
distributor repair the damage.
or serious injury.
0000008en

SAFETY
A WARNING A WARNING
BURN HAZARD!
SHOCK HAZARD!
• If you must drain the engine oil while it
• Turn off the battery switch (if
is still hot, stay clear of the hot engine
equipped) or disconnect the negative
oil to avoid being scalded. Make sure
battery cable before servicing the
you wear eye protection.
electrical system.
• Check the electrical harnesses for
or serious injury.
cracks, abrasions, and damaged or
0000011en
corroded connectors. ALWAYS keep
the connectors and terminals clean.
• Failure to comply could result in death A WARNING
or serious injury.
0000009en
A WARNING
BURN HAZARD!
• Wait until the engine cools before you
drain the engine coolant. Hot engine
coolant may splash and burn you.
SEVER HAZARD! • Failure to comply could result in death
or serious injury.
• Stop the engine before you begin to
0000016en
service it.
• NEVER leave the key in the key switch
when you are servicing the engine.
Someone may accidentally start the
engine and not realize you are
servicing it. This could result in a
serious injury.
• If you must service the engine while it
is operating, remove all jewelry, tie
back long hair, and keep your hands,
other body parts and clothing away
from moving / rotating parts.
or serious injury.
0000010en

SAFETY
A WARNING A CAUTION
BURN HAZARD!
• Keep your hands, and other body FLYING OBJECT HAZARD!
parts, away from hot engine surfaces
• ALWAYS wear eye protection when
such as the muffler, exhaust pipe,
servicing engine and when using
turbocharger (if equipped) and engine
compressed air or high-pressure
block during operation and shortly
water. Dust, flying debris, compressed
after you shut the engine down. These
air, pressurized water or steam may
surfaces are extremely hot while the
injure your eyes.
engine is operating and could
seriously burn you. • Failure to comply may result in minor
or moderate injury.
0000003en
or serious injury.
0000015en
CAUTION
A CAUTION • Only use diesel fuels recommended by
Yanmar for the best engine
performance, to prevent engine
damage and to comply with EPA / ARB
warranty requirements.
• Only use clean diesel fuel.
• NEVER remove primary strainer from
COOLANT HAZARD!
the fuel tank filler port (if equipped). If
• Wear eye protection and rubber gloves removed, dirt and debris could get into
when you handle Long Life or the fuel system causing it to clog.
Extended Life engine coolant. If 0000004en
contact with the eyes or skin should
occur, wash immediately with clean
water. CAUTION
• Failure to comply may result in minor NEVER attempt to adjust the low or high
or moderate injury. idle speed limit screw. This may impair
the safety and performance of the
0000005en
machine and shorten its life. If
adjustment is ever required, contact
your authorized Yanmar industrial
engine dealer or distributor.
0000045en

SAFETY
CAUTION CAUTION
If any problem is noted during the visual Observe the following environmental
check, the necessary corrective action operating conditions to maintain engine
should be taken before you operate the performance and avoid premature
engine. engine wear:
0000021en
• Avoid operating in extremely dusty
conditions.
CAUTION • Avoid operating in the presence of
NEVER hold the key in the START chemical gases or fumes.
position for longer than 15 seconds or • Avoid operating in a corrosive
the starter motor will overheat. atmosphere such as salt water spray.
0000007en
• NEVER install the engine in a
floodplain unless proper precautions
CAUTION are taken to avoid being subject to a
The illustrations and descriptions of flood.
optional equipment in this manual, such • NEVER expose the engine to the rain.
as the operator’s console, are for a 0000003enTNE
typical engine installation. Refer to the
documentation supplied by the optional
equipment manufacturer for specific
operation and maintenance instructions.
0000018en
CAUTION
If any indicator illuminates during
engine operation stop the engine
immediately. Determine the cause and
repair the problem before you continue
to operate the engine.
0000029en

SAFETY
CAUTION CAUTION
Observe the following environmental • Only use the engine oil specified.
operating conditions to maintain engine Other engine oils may affect warranty
performance and avoid premature coverage, cause internal engine
engine wear: components to seize, or shorten
• NEVER run the engine if the ambient engine life.
temperature is above +104°F (+40°C) • Prevent dirt and debris from
or below +5°F (-15°C). contaminating engine oil. Carefully
◆ If the ambient temperature exceeds clean the oil cap / dipstick and the
+104°F (+40°C) the engine may surrounding area before you remove
overheat and cause the engine oil to the cap.
break down. • NEVER mix different types of engine
◆ If the ambient temperature falls oil. This may adversely affect the
below +5°F (-15°C) rubber lubricating properties of the engine oil.
components such as gaskets and • NEVER overfill. Overfilling may result
seals will harden causing premature in white exhaust smoke, engine
engine wear and damage. overspeed or internal damage.
◆ Contact your authorized Yanmar
0000005en
industrial engine dealer or
distributor if the engine will be
operated in either temperature CAUTION
extreme. • Only use the engine coolant specified.
• Contact your authorized Yanmar Other engine coolants may affect
industrial engine dealer or distributor warranty coverage, cause an internal
if you need to operate the engine at build up of rust and scale and / or
high altitudes. At high altitudes the shorten engine life.
engine will lose power, run rough, and • Prevent dirt and debris from
produce exhaust gases that exceed contaminating engine coolant.
the design specifications. Carefully clean the radiator cap and
0000065enTNE the surrounding area before you
remove the cap.
• NEVER mix different types of engine
coolants. This may adversely affect the
properties of the engine coolant.
0000006en
CAUTION
• NEVER overfill the engine with engine
oil.
• ALWAYS keep the oil level between
upper and lower lines on the dipstick.
0000015en

SAFETY
CAUTION CAUTION
For maximum engine life, Yanmar New Engine Break In:
recommends that when shutting the • On the initial engine start-up, allow the
engine down, you allow the engine to engine to idle for approximately 15
idle, without load, for 5 minutes. This minutes while you check for proper
will allow the engine components that engine oil pressure, diesel fuel leaks,
operate at high temperatures, such as engine oil leaks, coolant leaks, and for
the turbocharger (if equipped) and proper operation of the indicators
exhaust system, to cool slightly before and / or gauges.
the engine itself is shut down.
0000008en
• During the first hour of operation, vary
the engine speed and load on the
engine. Short periods of maximum
CAUTION engine speed and load are desirable.
NEVER use an engine starting aid such Avoid prolonged operation at
as ether. Engine damage will result. minimum or maximum engine speeds
0000009en and loads for the next 4 to 5 hours.
• During the break-in period, carefully
CAUTION observe the engine oil pressure and
engine temperature.
Make sure the engine is installed on a
level surface. If a continuously running • During the break-in period, check the
engine is installed at an angle greater engine oil and coolant levels
than 20° (in any direction) or if an engine frequently.
runs for short periods of time (less than 0000011en
3 minutes) at an angle greater than 25°

in any direction, engine oil may enter the CAUTION
combustion chamber causing exessive
engine speed and generate white NEVER engage the starter motor while
smoke. This may cause serious engine the engine is running. This may damage
damage. the starter motor pinion and / or ring
gear.
0000010enTNE
0000012en

SAFETY
CAUTION CAUTION
• NEVER attempt to modify the engine’s Protect the air cleaner, turbocharger (if
design or safety features such as equipped) and electric components
defeating the engine speed limit from damage when you use steam or
control or the fuel injection quantity use high-pressure water to clean the
control. engine.
• Failure to comply may impair the 0000014en
engine’s safety and performance

characteristics and shorten the CAUTION
engine’s life. Any alterations to this
NEVER use high pressure water or
engine may affect the warranty
compressed air at greater than 28 psi or
coverage of your engine. See Yanmar
a wire brush to clean the radiator fins.
Limited Warranty on page 2-3.
Radiator fins damage easily.
0000044enTNESM
0000016en
CAUTION CAUTION
NEVER attempt to adjust the low or high
idle speed limit screw. This may impair
machine and shorten its life. If the idle
speed limit screws require adjustment,
Be environmentally responsible. Follow see your authorized Yanmar industrial
these procedures for hazardous waste engine dealer or distributor.
disposal. Failure to follow these 0000017en
procedures may seriously harm the
environment.
CAUTION
• Follow the guidelines of the EPA or
other governmental agency for the The tightening torque in the Standard
proper disposal of hazardous Torque Chart (page 5-17) should be
materials such as engine oil, diesel applied only to the bolts with a “7” head.
fuel and engine coolant. Consult the (JIS strength classification: 7T)
local authorities or reclamation facility. • Apply 60% torque to
• NEVER dispose of hazardous bolts that are not listed.
materials irresponsibly by dumping • Apply 80% torque when
them into a sewer, on the ground or tightened to aluminum alloy.
into ground water or waterways. 0000023enTNESM
0000013en

SAFETY
CAUTION CAUTION
If any indicator fails to illuminate when If the fuel filter / water separator is
the key switch is in the ON position, see positioned higher than the fuel level in
your authorized Yanmar industrial the fuel tank, water may not drip out
engine dealer or distributor for service when the fuel filter / water separator
before operating the engine. drain cock is opened. If this happens,
0000028en turn the air vent screw on the top of the
fuel filter / water separator 2-3 turns
counterclockwise.
CAUTION
Be sure to tighten the air vent screw
Establish a periodic maintenance plan
after the water has drained out.
according to the engine application and
0000025en
make sure you perform the required
periodic maintenance at intervals
indicated. Failure to follow these CAUTION
guidelines will impair the engine’s safety • When the engine is operated in dusty
and performance characteristics, conditions, clean the air cleaner
shorten the engine’s life and may affect element more frequently.
the warranty coverage on your engine.
See Yanmar Limited Warranty on • NEVER operate the engine with the air
page 2-3. cleaner or element(s) removed. This
may cause foreign material to enter the
Consult your authorized Yanmar engine and damage it.
industrial engine dealer or distributor for
0000026en
assistance when checking items marked
with a z.
0000024enTNESM CAUTION
The maximum air intake restriction shall
CAUTION be 0.90 psi (6.23 kPa; 635 mm Aq) or
less. Clean or replace the air cleaner
It is important to perform daily checks element if the air intake restriction
See Daily on page 5-19. exceeds the above mentioned value.
Periodic maintenance prevents 0000046en
unexpected downtime, reduces the
number of accidents due to poor
machine performance and helps extend
CAUTION
the life of the engine. NEVER turn off the battery switch (if
0000060enTNESM
equipped) or short the battery cables
during operation. Damage to the electric
system will result.
0000061en

Section 4
GENERAL SERVICE
INFORMATION
TNE Service Manual
Table of Contents
Page
Component Identification................................................................. 4-3
Location of Labels ........................................................................... 4-3
EPA / ARB Emission Control Regulations - USA Only.................... 4-4
Emission Control Labels.................................................................. 4-4
EPA / ARB Labels ..................................................................... 4-4
The 97/68/EC Directive Certified Engines....................................... 4-4
Engine Family.................................................................................. 4-5
Function of Major Engine Components ........................................... 4-6
Function of Cooling System Components ....................................... 4-8
Diesel Fuel ...................................................................................... 4-9
Diesel Fuel Specifications ......................................................... 4-9
Filling The Fuel Tank ............................................................... 4-10
Priming the Fuel System ......................................................... 4-12
Engine Oil...................................................................................... 4-14
Engine Oil Specifications......................................................... 4-14
Engine Oil Viscosity................................................................. 4-14
Checking Engine Oil ................................................................ 4-15
Adding Engine Oil.................................................................... 4-15
Engine Oil Capacity (Typical) .................................................. 4-15
Engine Coolant.............................................................................. 4-16
Engine Coolant Specifications................................................. 4-16
Filling Radiator With Engine Coolant....................................... 4-17
Engine Coolant Capacity (Typical) .......................................... 4-18
Specifications ................................................................................ 4-19
Description of Model Number .................................................. 4-19

GENERAL SERVICE INFORMATION
Engine Speed Specifications................................................... 4-19
Engine General Specifications ................................................ 4-19
Principal Engine Specifications ..................................................... 4-20
4TNE92-NMH.......................................................................... 4-20
4TNE92-NMHA ....................................................................... 4-21
4TNE98-NMH.......................................................................... 4-22
Engine Service Information ........................................................... 4-23
Engine Tuning ......................................................................... 4-23
Tightening Torques for Standard Bolts and Nuts .......................... 4-24
Standard Torque Chart.................................................................. 4-25
Abbreviations and Symbols........................................................... 4-26
Abbreviations........................................................................... 4-26
Symbols................................................................................... 4-26
Unit Conversions ........................................................................... 4-27
Unit Prefixes ............................................................................ 4-27
Units of Length ........................................................................ 4-27
Units of Volume ....................................................................... 4-27
Units of Mass........................................................................... 4-27
Units of Force .......................................................................... 4-27
Units of Torque........................................................................ 4-27
Units of Pressure..................................................................... 4-27
Units of Power ......................................................................... 4-27
Units of Temperature............................................................... 4-27

COMPONENT IDENTIFICATION LOCATION OF LABELS

Figure 4-1 shows where major engine components Figure 4-2 shows the location of regulatory and
are located. safety labels on Yanmar TNE series engines.
(2) (1)
(2)
(6) (15)
(12)
(10)
(11)
(1)
(9)
0000585A
Figure 4-2
(4)
(13) The typical location of the emission control
(8) information label is shown (Figure 4-2, (1)).
(3) Typical location of the engine nameplate is shown
(14)
(7) (5) (Figure 4-2, (2)).
0001102A
Figure 4-1 Engine Nameplate (Typical)
1. Fuel Filter / Water 8. Engine Oil Filter

Separator 9. Dipstick
2. Top Filler Port (Engine Oil)
(Engine Oil) 10. Engine Coolant
3. Governor Lever Pump
4. Fuel Injection 11. Alternator
Pump 12. Glow Plug
5. Side Filler Port 13. V-Belt
(Engine Oil) 14. Crankshaft
6. Fuel Priming V-Pulley
Pump 15. Starter Motor
7. Drain Plug
(Engine Oil)
0000287

EPA / ARB EMISSION CONTROL EPA / ARB Labels

REGULATIONS - USA ONLY
Yanmar TNE engines meet Environmental
Protection Agency (EPA) (U. S. Federal) emission
control standards as well as the California Air " "
Resources Board (ARB, California) regulations.

Only engines that conform to ARB regulations can
be sold in the State of California.
Refer to the specific EPA / ARB installation (page
5-16) and maintenance (page 5-16) in the
Periodic Maintenance section of this manual. Also
(EPA) Less Than 50 HP SAE (37kW)
refer to the Yanmar Co., Ltd. Limited Emission
Control System Warranty - USA Only on page 2-5.
EMISSION CONTROL LABELS

Since emission control regulations are being issued
on a global basis, it is necessary to identify which
regulations a particular engine complies with. We
have listed several different types of labels you
might find on your engine.
(EPA & ARB)
THE 97/68/EC DIRECTIVE

CERTIFIED ENGINES
The engines described in this manual have been
certified by the 97/68/EC Directive.
To identify the engines that meet this certification,
the 97/68/EC emission control label is affixed on
the engines.
97/68/EC DIRECTIVE
(97/68/EC)

ENGINE FAMILY
The EPA / ARB labels and the 97/68/EC label all
have an Engine Family field. The following is an
explanation of the Engine Family designation:
3 YDX L 1.33 M 3 N
Method of air aspiration
Number of cylinders
Engine speed specifications
Displacement (liter)
Non-road / Off-road engine
Yanmar Diesel
*2003 Model Year
3*: 2003
4 : 2004
5 : 2005

FUNCTION OF MAJOR ENGINE COMPONENTS

Components Functions
Air Cleaner The air cleaner prevents airborne contaminants from entering the
engine. Since the air cleaner is application specific, it must be
carefully selected by an application engineer. It is not part of the
basic engine package as shipped from the Yanmar factory.
Periodic replacement of the air cleaner filter element is necessary.
See the Periodic Maintenance Schedule on page 5-17 for the
replacement frequency.
Alternator The alternator is driven by a V-belt which is powered by the
crankshaft V-pulley. The alternator supplies electricity to the
engine systems and charges the battery while the engine is
running.
Dipstick (Engine Oil) The engine oil dipstick is used to determine the amount of engine
oil in the crankcase.
Electric Fuel Pump The electric fuel pump makes sure there is a constant supply of
diesel fuel to the fuel injection pump. The electric fuel pump is
electro-magnetic and runs on 12 VDC. An electric fuel pump may
be installed as an option or as standard equipment. Standard
equipment may vary based on engine model and specification. If
an electric fuel pump is installed, turn the key switch to the ON
position for 10 to 15 seconds to prime the fuel system.
Engine Oil Filter The engine oil filter removes contaminants and sediments from
the engine oil. Periodic replacement of the engine oil filter is
necessary. See the Periodic Maintenance Schedule on page 5-17
for the replacement frequency.
Fuel Filter The fuel filter removes contaminants and sediments from the
diesel fuel. Periodic replacement of the fuel filter is necessary. See
the Periodic Maintenance Schedule on page 5-17 for the
replacement frequency. Please note that the word “diesel” is
implied throughout this manual when the word “fuel” is used.
Fuel Filter / Water Separator The fuel filter / water separator removes contaminants, sediments
and water from diesel fuel going to the fuel filter. This is a required
component of the fuel system. This is standard equipment with
every engine. The separator is installed between the fuel tank and
the fuel pump. Periodically drain the water from the fuel filter /
water separator using the drain cock at the bottom of the
separator.

Fuel Priming Lever If the unit has a mechanical fuel pump, a fuel priming lever on the
mechanical fuel pump primes the fuel system. The fuel system
needs to be primed before you start the engine for the first time, if
you run out of fuel, or if fuel system service is performed. To prime
the fuel system, operate the fuel priming lever until the cup in the
fuel filter is full of fuel.
Fuel Tank The fuel tank is a reservoir that holds diesel fuel. When fuel leaves
the fuel tank it goes to the fuel filter / water separator. Next, fuel is
pumped to the fuel filter by the fuel pump. Next the fuel goes to the
fuel injection pump. Since fuel is used to keep the fuel injection
pump cool and lubricated, more fuel than necessary enters the
injection pump. When the injection pump pressure reaches a
preset value, a relief valve allows excess fuel to be returned back
to the fuel tank. The fuel tank is a required engine component.
Mechanical Fuel Pump The mechanical fuel pump is a diaphragm type of pump and is
installed on the fuel injection pump body. The mechanical fuel
pump is driven by a cam on the camshaft of the fuel injection
pump. An electric fuel pump is available as an option. The
mechanical fuel pump is not installed on the fuel injection pump if
the electric fuel pump option is installed.
Side and Top Filler Port (Engine Oil) You can fill the crankcase with engine oil from either the side or
top filler port depending upon which one is most convenient.
Starter Motor The starter motor is powered by the battery. When you turn the
key switch in the operator’s console to the START position, the
starter motor engages with the ring gear installed on the flywheel
and starts the flywheel in motion.

FUNCTION OF COOLING SYSTEM COMPONENTS

The TNE engine is liquid-cooled by means of a cooling system.
The cooling system consists of a radiator, radiator cap, engine
cooling fan, engine coolant pump, thermostat, and reserve tank.
Note that all cooling system components are required for
Cooling System proper engine operation. Since some of the components are
application specific, they must be carefully selected by an
application engineer. The application specific items are not
part of the basic engine package as shipped from the Yanmar
factory.
• Engine Cooling Fan The engine cooling fan is driven by a V-belt which is powered by
the crankshaft V-pulley. The purpose of the engine cooling fan is
to circulate air through the radiator.
• Engine Coolant Pump The engine coolant pump circulates the engine coolant through
the cylinder block and cylinder head and returns the engine
coolant to the radiator.
• Radiator The radiator acts as a heat exchanger. As the engine coolant
circulates through the cylinder block it absorbs heat. The heat in
the engine coolant is dissipated in the radiator. As the engine
cooling fan circulates air through the radiator, the heat is
transferred to the air.
• Radiator Cap The radiator cap controls the cooling system pressure. The
cooling system is pressurized to raise the boiling point of the
engine coolant. As the engine coolant temperature rises, the
system pressure and the coolant volume increases. When the
pressure reaches a preset value, the release valve in the radiator
cap opens and the excess engine coolant flows into the reserve
tank. As the engine coolant temperature is reduced, the system
pressure and volume is reduced and the vacuum valve in the
radiator cap opens allowing engine coolant to flow from the
reserve tank back into the radiator.
• Reserve Tank The reserve tank contains the overflow of engine coolant from the
radiator. If you need to add engine coolant to the system, add it to
the reserve tank, not the radiator.
• Thermostat A thermostat is placed in the cooling system to prevent engine
coolant from circulating into the radiator until the engine coolant
temperature reaches a preset temperature. When the engine is
cold, no engine coolant flows through the radiator. Once the
engine reaches its operating temperature the thermostat opens.
By letting the engine warm up as quickly as possible, the
thermostat reduces engine wear, deposits and emissions.

DIESEL FUEL • Carbon residue content not to exceed 0.35% by

volume. Less than 0.1% is preferred.
Diesel Fuel Specifications • Total aromatics content should not exceed 35%
Diesel fuel should comply with the following by volume. Less than 30% is preferred.
specifications. The table lists several worldwide
• PAH (polycyclic aromatic hydrocarbons) content
specifications for diesel fuels.
should be below 10% by volume.
Diesel Fuel
Location
• Metal content of Na, Mg, Si, and Al should be
Specification equal to or lower than 1 mass ppm. (Test analysis
No. 2-D, No. 1-D, ASTM USA method JPI-5S-44-95)
D975-94
• Lubricity: Wear mark of WS1.4 should be Max.
EN590:96 European Union 0.018 in (460 µm) at HFRR test.
ISO 8217 DMX International
BS 2869-A1 or A2 United Kingdom Bio-Diesel Fuels
JIS K2204 Grade No.2 Japan In Europe and in the United States, as well as some
KSM-2610 Korea
other countries, non-mineral oil based fuel
resources such as RME (Rapeseed Methyl Ester)
GB252 China and SOME (Soybean Methyl Ester), collectively
known as FAME (Fatty Acid Methyl Esters), are
Additional Technical Fuel Requirements being used as extenders for mineral oil derived
• The fuel cetane number should be equal to 45 or diesel fuels.
higher.
Yanmar approves the use of bio-diesel fuels that do
• The sulfur content must not exceed 0.5% by not exceed a blend of 5% (by volume) of FAME with
volume. Less than 0.05% is preferred. 95% (by volume) of approved mineral oil derived
diesel fuel. Such bio-diesel fuels are known in the
• Bio-Diesel fuels. See Bio-Diesel Fuels on marketplace as B5 diesel fuels.
page 4-9.
These B5 diesel fuels must meet certain
• NEVER mix kerosene, used engine oil, or requirements.
residual fuels with the diesel fuel.
1. The bio-fuels must meet the minimum
• Water and sediment in the fuel should not exceed specifications for the country in which they are
0.05% by volume. used.
• Keep the fuel tank and fuel-handling equipment • In Europe, bio-diesel fuels must comply with
clean at all times. the European Standard EN14214.
• Poor quality fuel can reduce engine performance • In the United States, bio-diesel fuels must
and / or cause engine damage. comply with the American Standard ASTM
D-6751.
• Fuel additives are not recommended. Some fuel
2. Bio-fuels should be purchased only from
additives may cause poor engine performance.
recognized and authorized diesel fuel suppliers.
Consult your Yanmar representative for more
information. Precautions and concerns regarding the use of
bio-fuels:
• Ash content not to exceed 0.01% by volume.
1. Free methanol in FAME may result in corrosion
of aluminum and zinc FIE components.

2. Free water in FAME may result in plugging of Filling The Fuel Tank
fuel filters and increased bacterial growth.
3. High viscosity at low temperatures may result in A DANGER
fuel delivery problems, injection pump seizures,
and poor injection nozzle spray atomization.
4. FAME may have adverse effects on some
elastomers (seal materials) and may result in
fuel leakage and dilution of the engine
lubricating oil. FIRE AND EXPLOSION HAZARD!
5. Even bio-diesel fuels that comply with a suitable • Diesel fuel is extremely flammable and
standard as delivered, will require additional explosive under certain conditions.
care and attention to maintain the quality of the • Only fill fuel tank with diesel fuel.
fuel in the equipment or other fuel tanks. It is Filling fuel tank with gasoline may
important to maintain a supply of clean, fresh result in a fire.
fuel. Regular flushing of the fuel system, and / • NEVER refuel with engine running.
or fuel storage containers, may be necessary.
• Wipe up all spills immediately.
6. The use of bio-diesel fuels that do not comply
with the standards as agreed to by the diesel • Keep sparks, open flames or any other
engine manufacturers and the diesel fuel form of ignition (match, cigarette,
injection equipment manufacturers, or static electric source) away when
bio-diesel fuels that have degraded as per the fueling / refueling.
precautions and concerns above, may affect • NEVER overfill the fuel tank.
the warranty coverage of your engine. See
Yanmar Co., Ltd. Limited Emission • Fill fuel tank and store fuel in a
Control System Warranty - USA Only on well-ventilated area only.
page 2-5. • Failure to comply will result in death or
serious injury.
0000005en

A DANGER A DANGER

• Be sure to place the diesel fuel • Before you operate the engine, check
container on the ground when for fuel leaks. Replace rubberized fuel
transferring diesel fuel from the pump hoses every two years or every 2000
to the container. Hold the hose nozzle hours of engine operation, whichever
firmly against the side of the container comes first, even if the engine has
while filling it. This prevents static been out of service. Rubberized fuel
electricity build-up which could cause lines tend to dry out and become
sparks and ignite fuel vapors. brittle after two years or 2000 hours of
engine operation, whichever comes
• NEVER place diesel fuel or other
first.
flammable material such as oil, hay or
dried grass close to the engine during • Failure to comply will result in death or
engine operation or shortly after shut serious injury.
down. 0000015en

serious injury. CAUTION
0000014en
• Only use diesel fuels recommended by
Yanmar for the best engine
performance, to prevent engine
damage and to comply with EPA / ARB
warranty requirements.
• Only use clean diesel fuel.
• NEVER remove primary strainer from
the fuel tank filler port (if equipped). If
removed, dirt and debris could get into
the fuel system causing it to clog.
0000004en
Note that a typical fuel tank is shown. The fuel tank

on your equipment may be different.
1. Clean the area around the fuel cap
(Figure 4-2, (1)).
2. Remove the fuel cap (Figure 4-2, (1)) from the
fuel tank (Figure 4-2, (2)).

3. Observe the fuel level sight gauge Priming the Fuel System
(Figure 4-2, (3)) and stop fueling when gauge
shows fuel tank is full. NEVER overfill the fuel
tank.
A DANGER
4. Replace the fuel cap (Figure 4-2, (1)) and hand
tighten. Over-tightening the fuel cap will
damage it.
(1)
(2) • Place an approved container under the

air bleed port when you prime the fuel
system. Never use a shop rag to catch
the fuel. Wipe up any spills
(3) immediately. ALWAYS close the air
the system.
0000002A
Figure 4-3 is under pressure and fuel could spray
out when you open the air bleed port.
• If the unit has an electric fuel pump,
turn the key switch to the ON position
for 10 to 15 seconds, or until the fuel
of bubbles, to allow the electric fuel
pump to prime the system.
• If the unit has a mechanical fuel pump,
operate the fuel priming pump several
times until the fuel coming out of the
air bleed port is free of bubbles.
serious injury.
0000006en

6. NEVER use the starter motor to crank the
CAUTION engine in order to prime the fuel system. This
may cause the starter motor to overheat and
damage the coils, pinion and / or ring gear.
To prime the fuel system on engines not equipped
with an electric fuel system:
Be environmentally responsible. Follow 1. Place an approved container under the air

these procedures for hazardous waste bleed port.
disposal. Failure to follow these 2. Loosen the air bleed port (Figure 4-4, (1)) 2 or
procedures may seriously harm the 3 turns.
environment. 3. Operate the fuel priming pump (Figure 4-4, (2))
• Follow the guidelines of the EPA or until the fuel coming out of the air bleed port is
other governmental agency for the free of bubbles.
proper disposal of hazardous 4. Tighten the air bleed port.
materials such as engine oil, diesel
5. Wipe up any spills and properly dispose of fuel.
fuel and engine coolant. Consult the
local authorities or reclamation facility. 6. NEVER use the starter motor to crank the
engine in order to prime the fuel system. This
• NEVER dispose of hazardous may cause the starter motor to overheat and
materials irresponsibly by dumping damage the coils, pinion and / or ring gear.
them into a sewer, on the ground or
into ground water or waterways. (2)
0000013en
(1)
The fuel system needs to be primed under certain
conditions.
• Before starting the engine for the first time.
• After running out of fuel and fuel has been added
to the fuel tank.
• After fuel system maintenance such as changing
0000862B
the fuel filter and draining the fuel filter / water
separator, or replacing a fuel system component.
To prime the fuel system on engines equipped with Figure 4-4
an electric fuel pump:
1. Place an approved container under the air
bleed port.
2. Loosen the air bleed port 2 or 3 turns.
3. Turn the key to the ON position for 10 to 15
seconds or until the fuel coming out of the air
bleed port is free of bubbles.
4. Tighten the air bleed port.
5. Wipe up any spills and properly dispose of fuel.

ENGINE OIL 2. Change the engine oil after the first 50 hours
of operation and then at every 250 hours
thereafter.
CAUTION
3. Select the oil viscosity based on the ambient
• Only use the engine oil specified. temperature where the engine is being
Other engine oils may affect warranty operated. See the SAE Service Grade
coverage, cause internal engine Viscosity Chart (Figure 4-5).
components to seize, or shorten
engine life. 4. Yanmar does not recommend the use of
engine oil “additives.”
• Prevent dirt and debris from
contaminating engine oil. Carefully Additional Technical Engine oil
clean the oil cap / dipstick and the Requirements:
surrounding area before you remove
The engine oil must be changed when the Total
the cap.
Base Number (TBN) has been reduced to 2.0. TBN
• NEVER mix different types of engine (mgKOH/g) test method; JIS K-201-5.2-2 (HCI),
oil. This may adversely affect the ASTM D4739 (HCI).
lubricating properties of the engine oil.
• NEVER overfill. Overfilling may result Engine Oil Viscosity
in white exhaust smoke, engine Select the appropriate engine oil viscosity based on
overspeed or internal damage. the ambient temperature and use the SAE Service
0000005en Grade Viscosity Chart in Figure 4-5.
Engine Oil Specifications

SAE 10W
Use an engine oil that meets or exceeds the SAE 20W
following guidelines and classifications:
SAE 10W-30
Service Categories SAE 15W-40

SAE 20
• API Service Categories CD or higher SAE 30
• ACEA Service Categories E-3, E-4, and E-5 SAE 40
• JASO Service Category DH-1

-4˚F 14˚F 32˚F 50˚F 68˚F 86˚F 104˚F
(-20˚C) (-10˚C) (0˚C) (10˚C) (20˚C) (30˚C) (40˚C)
Definitions 0000005
• API Classification (American Petroleum Institute)
Figure 4-5
• ACEA Classification (Association des
Constructeurs Européens d'Automobilies)
• JASO (Japanese Automobile Standards
Organization)
Note:
1. Be sure the engine oil, engine oil storage
containers, and engine oil filling equipment
are free of sediments and water.

Checking Engine Oil Engine Oil Capacity (Typical)
1. Make sure engine is level. Note: These are the engine oil capacities
associated with a “Deep Standard” oil
2. Remove dipstick (Figure 4-6, (1)) and wipe with pan. Oil capacity will vary dependant
clean cloth. upon which optional oil pan is used.
3. Fully reinsert dipstick. Refer to the operation manual provided
4. Remove dipstick. The oil level should be by the driven machine manufacturer for
between upper (Figure 4-6, (2)) and lower the actual engine oil capacity of your
(Figure 4-6, (3)) lines on the dipstick. machine.
5. Fully reinsert dipstick. The following are typical engine oil capacities for
4TNE92-NMH, 4TNE92-NMHA, and 4TNE98-NMH
(4) engines.
(5)
(1) Dipstick Upper
Engine Model
Limit / Lower Limit
4TNE92-NMH
9.7 / 7.6 qt
4TNE92-NMHA
(9.2 / 7.2 L)
4TNE98-NMH
(2)
(3)
(4)
(5)
0001108A
Figure 4-6
Adding Engine Oil

1. Make sure engine is level.
2. Remove oil cap (Figure 4-6, (4)).
3. Add indicated amount of engine oil at the top or
side engine oil filler port (Figure 4-6, (5)).
4. Wait three minutes and check oil level.
5. Add more oil if necessary.
6. Replace oil cap (Figure 4-6, (4)) and hand
tighten. Over-tightening may damage the cap.

ENGINE COOLANT
A CAUTION
A DANGER
COOLANT HAZARD!
• Wear eye protection and rubber gloves
SCALD HAZARD!
when you handle Long Life or
• NEVER remove the radiator cap if the Extended Life engine coolant. If
engine is hot. Steam and hot engine contact with the eyes or skin should
coolant will spurt out and seriously occur, wash immediately with clean
burn you. Allow the engine to cool water.
down before you attempt to remove
the radiator cap. • Failure to comply may result in minor
or moderate injury.
• Securely tighten the radiator cap after 0000005en
you check the radiator. Steam can
spurt out during engine operation if
the cap is loose. CAUTION
• ALWAYS check the level of engine • Only use the engine coolant specified.
coolant by observing the reserve tank. Other engine coolants may affect
warranty coverage, cause an internal
• Failure to comply will result in death or build up of rust and scale and / or
serious injury. shorten engine life.
0000002en
contaminating engine coolant.
A WARNING Carefully clean the radiator cap and
the surrounding area before you
remove the cap.
BURN HAZARD!
0000006en
drain the engine coolant. Hot engine Engine Coolant Specifications
Use a Long Life Coolant (LLC) or an Extended Life
• Failure to comply could result in death Coolant (ELC) that meets or exceeds the following
or serious injury. guidelines and specifications.
0000016en
Alternative Engine Coolant
If an Extended or Long Life Coolant is not available,
alternatively, you may use an ethylene glycol or
propylene glycol based conventional coolant
(green).

Notes:
(2)
1. ALWAYS use a mix of coolant and water.
NEVER use water only. (5)
2. Mix coolant and water per the mixing
instructions on the coolant container. (3)
3. Water quality is important to coolant
performance. Yanmar recommends that soft, (6) FULL
LOW
distilled, or demineralized water be used to (4)

mix with coolants.
4. NEVER mix extended or long life coolants
and conventional (green) coolants.
(1)
5. NEVER mix different types and / or colors of 0000029A
extended life coolants.
Figure 4-7
6. Replace the coolant every 1000 engine hours
or once a year.
Additional Technical Coolant

Specifications:
• ASTM D6210, D4985 (US)
• JIS K-2234 (Japan)
(1)
• SAE J814C, J1941, J1034 or J2036
(International)
Filling Radiator With Engine Coolant

Fill the radiator and reserve tank as follows. This
procedure is for filling the radiator for the first time
or refilling it after it is flushed. Note that a typical 0001578A
radiator is illustrated.
Figure 4-8
1. Check to be sure the radiator drain plug is
installed and tightened or the drain cock 2. Remove the radiator cap (Figure 4-7, (2)) by
(Figure 4-7, (1)) is closed. Also make sure the turning it counter-clockwise about 1/3 of a turn.
cylinder block drain plug (Figure 4-8, (1)) is
installed and tightened.

3. Pour the engine coolant slowly into the radiator Engine Coolant Capacity (Typical)
until it is even with the lip of the engine coolant Note: Capacities listed are for the engine only
filler port. Make sure that air bubbles do not without a radiator. Refer to the operation
develop as you fill the radiator. manual provided by the driven machine
4. Reinstall the radiator cap (Figure 4-7, (2)). manufacturer for the total cooling system
Align the tabs on the back side of the radiator capacity of your specific machine.
cap with the notches on the engine coolant filler
The following are typical engine coolant capacities
port. Press down and turn the cap clockwise
for 4TNE92-NMH, 4TNE92-NMHA, and
about 1/3 of a turn.
4TNE98-NMH engines.
5. Remove the cap of the reserve tank
(Figure 4-7, (3)), and fill it to the LOW (COLD) Engine Coolant
mark (Figure 4-7, (4)) with engine coolant. Engine Model
Capacity
Reinstall the cap.
4TNE92-NMH
6. Check the hose (Figure 4-7, (5)) that connects 4TNE92-NMHA 1.11 gal. (4.2 L)
the reserve tank (Figure 4-7, (3)) to the 4TNE98-NMH
radiator. Be sure it is securely connected and
there are no cracks or damage. If the hose is
damaged, engine coolant will leak out instead
of going into the reserve tank.
7. Run the engine until it is at operating
temperature. Check the level of engine coolant
in the reserve tank. When the engine is running
and the engine coolant is at normal
temperature, the coolant level in the tank should
be at the FULL (HOT) mark (Figure 4-7, (6)). If
the engine coolant is not at the FULL (HOT)
mark, add additional engine coolant to the
reserve tank to bring the level to the FULL
(HOT) mark.

SPECIFICATIONS
Description of Model Number
4 TNE 92 - OO
Customer / Machine Code
Cylinder Bore (in terms of mm)
Yanmar Diesel Engine Series
Number of Cylinders (4)
Engine Speed Specifications

NOTATION AVAILABLE ENGINE SPEED INTENDED USES
VM 2000 ~ 2500 rpm (min-1) Agricultural, Constructive, Industrial Machines
VM: Variable Medium Speed
Engine General Specifications

Type Vertical Inline, Water Cooled, 4-Cycle Diesel Engine
Combustion System Indirect Injection
Starting System Electric Starting
Cooling System Radiator
Lubricating System Forced Lubrication With Trochoid Pump
PTO Position Flywheel End
Direction of Rotation Counterclockwise Viewed from Flywheel Side
Notes:
1. The information described in Principal Engine Specifications is for a “standard” engine. To obtain the
information for the engine installed in your driven machine, please refer to the manual provided by the
driven machine manufacturer.
2. Engine rating conditions are as follows (SAE J1349, ISO 3046/1):
• Atmospheric Condition: Room temperature 77°F (25°C), Atmospheric pressure 29.53 in Hg (100 kPa,
750 mm Hg), Relative humidity 30%
• Fuel Temperature at Fuel Injector Pump Inlet: 104°F (40°C)
• With Cooling Fan, Air Cleaner, Muffler: Yanmar Standard
• After Engine Break-In Period. Output Allowable Deviation: ± 3%
• 1 PS = 0.7355 kW
• 1 hp SAE (Society of Automotive Engineers)= 0.7457 kW

PRINCIPAL ENGINE SPECIFICATIONS

4TNE92-NMH
Engine Model 4TNE92-NMH
Version VM
Type Vertical Inline Diesel Engine
Aspiration Natural
No. of Cylinders 4
Bore × Stroke 3.62 x 3.94 in (92 × 100 mm)
Displacement 162.3 cu in (2.659 L)
Max. Rated Output (Net) rpm
2450
(min-1)
hp SAE 45.1
kW 33.6
PS 45.7
High Idle Speed
2725 ± 25 rpm
(Bare Engine)
Low Idle Speed
850 ± 25 rpm
(Bare Engine)
Engine Weight (Dry)* 491.6 lb (194 kg)
PTO Position Flywheel Side
Direction of Rotation Counterclockwise Viewed From Flywheel Side
Cooling System Liquid-Cooled With Radiator
At normal operating speeds, oil pressure is: 42 - 57 psi (0.29 - 0.39 MPa; 3.0 - 4.0 kgf/cm2)
At idle, oil pressure is: No less than 8.5 psi (0.06 MPa; 0.6 kgf/cm2)
Starting System Electric Starting - Starter Motor: DC12V, 3.1 hp (2.3 kW)
Alternator: DC12V, 60A
Recommended Battery Capacity: 12V, 622 CCA (Cold Cranking Amps)
Dimensions (L × W × H)* 24.9 x 19.6 x 28.0 in
(632 x 498 x 711 mm)
Engine Oil Pan Capacity 9.7 / 7.6 qt (9.2 / 7.2 L)
(Dipstick Upper Limit / Lower Limit)
Engine Coolant Capacity 1.11 gal (4.2 L) Engine Only
* Engine specifications do not include height of

lifting eyes nor dimensions or specifications for the
Cooling Fan, Radiator, Muffler, and Air Cleaner.

4TNE92-NMHA
Engine Model 4TNE92-NMHA
Version VM
Aspiration Natural
No. of Cylinders 4
2050
(min-1)
hp SAE 39.0
kW 29.1
PS 39.6
High Idle Speed
2450 ± 25 rpm
(Bare Engine)
Low Idle Speed
850 ± 25 rpm
(Bare Engine)
(632 x 498 x 676 mm)
* Engine Specifications Without Cooling Fan,

Radiator, Muffler, and Air Cleaner.

4TNE98-NMH
Engine Model 4TNE98-NMH
Version VM
Aspiration Natural
No. of Cylinders 4
2400
(min-1)
hp SAE 63.6
kW 47.4
PS
High Idle Speed 2725 ± 25 64.4
(Bare Engine) rpm
Low Idle Speed
850 ± 25 rpm
(Bare Engine)
(632 x 498 x 711 mm)
* Engine Specifications Without Cooling Fan,

Radiator, Muffler, and Air Cleaner.

ENGINE SERVICE INFORMATION

Engine Tuning
Inspection Item Standard Limit
0.006 - 0.010 in
Intake / Exhaust Valve Gap -
(0.15 - 0.25 mm)
1711 - 1842 psi
Fuel Injection Pressure (11.8 - 12.7 MPa -
120 - 130 kgf / cm²)
Fuel Injection Timing with Plunger Lifted 0.039 in
6°±1°ATDC -
(1 mm)
425 - 428 psi 341 psi
Compression Pressure at 250 rpm (250 min¯¹) (2.93 - 2.95 MPa (2.35 MPa
29 - 31 kgf / cm²) 24 kgf / cm²)
Max. (when cold) 86 psi (0.59 MPa,
-
6.0 kgf/cm2)
At rated output 42 - 57 psi (0.29 - 0.39 MPa,
Lubricating Oil Pressure -
2.96 - 3.98 kgf/cm2)
When idling 8.5 psi (0.06 MPa,
-
0.6 kgf/cm2) or greater
Full Opening Lift
Valve Opening Temperature
Temperature
Thermostat 0.32 in (8 mm) or
160°F
Above
(71°C)
185°F (85°C)

TIGHTENING TORQUES FOR STANDARD BOLTS AND NUTS

Nominal Thread
Item x Pitch Tightening Torque Remarks
Diameter
7 to 9 ft lbs Use 80% of the value at left
(87 to 104 in lbs, when the tightening part is
M6 x 1.0 mm
9.8 to 11.8 N·m, aluminum.
1.0 to 1.2 kgf·m) Use 60% of the value at left
17 to 21 ft lbs for 4T bolts and lock nuts.
(200 to 251 in lbs,
M8 x 1.25 mm
22.6 to 28.4 N·m,
2.3 to 2.9 kgf·m)
33 to 40 ft lbs
Hexagon Bolt (7T) M10 x 1.5 mm (44.1 to 53.9 N·m,
and Nut 4.5 to 5.5 kgf·m)
58 to 72 ft lbs
M12 x 1.75 mm (78.4 to 98.0 N·m,
8.0 to 10 kgf·m)
94 to 108 ft lbs
M14 x 1.5 mm (127.5 to 147.1 N·m,
13 to 15 kgf·m)
159 to 174 ft lbs
M16 x 1.5 mm (215.7 235.4 N·m,
22 to 24 kgf·m)
7 ft lbs
1/8 mm
(87 in lbs, 9.8 N·m, 1.0 kgf·m)
14 ft lbs
1/4 mm (173 in lbs, 19.6 N·m, 2.0
PT PLug kgf·m) -
22 ft lbs
3/8 mm
(29.4 N·m, 3.0 kgf·m)
43 ft lbs
1/2 mm
(58.8 N·m, 6.0 kgf·m)
9 to 12 ft lbs
(112 to 148 in lbs,
M8
12.7 to 16.7 N·m,
1.3 to 1.7 kgf·m)
14 to 19 ft lbs
(173 to 225 in lbs,
M10
19.6 to 18.734 N·m,
2.0 to 3.5 kgf·m)
Pipe Joint Bolt 18 to 25 ft lbs -
M12 (24.5 to 34.3 N·m,
2.5 to 3.5 kgf·m)
29 to 36 ft lbs
M14 (39.2 to 49.0 N·m,
4.0 to 5.0 kgf·m)
36 to 43 ft lbs
M16 (49.0 to 58.8 N·m,
5.0 to 6.0 kgf·m)
Note: Lubricating oil is not applied to threaded portion and seat surface.

STANDARD TORQUE CHART

Thread size × Pitch mm M6×1.0 M8×1.25 M10×1.5 M12×1.75 M14×1.5 M16×1.5
in lbs 96.0 ± 9.0 - - - - -
ft lbs - 19.0 ± 2.0 36.0 ± 4.0 65.0 ± 7.0 101.0 ± 7.0 167.0 ± 7.0
Tightening Torque
N·m 10.8 ± 1.0 25.5 ± 2.9 49.0 ± 4.9 88.3 ± 9.8 137 ± 9.8 22.6 ± 9.8
kgf·m 1.1 ± 0.1 2.6 ± 0.3 5.0 ± 0.5 9.0 ± 1.0 14.0 ± 1.5 23.0 ± 2.0

ABBREVIATIONS AND kgf/cm² kilogram force per square

centimeter
SYMBOLS kgf·m kilogram force meter
km kilometers
Abbreviations kPa kilopascal
kW kilowatt
A ampere
L liter
AC alternating current
L/hr liter per hour
ACEA Association des Constructeurs
lb pound
Européens d’Automobilies
lbf pond force
Ah ampere-hour
mL milliliter
approx. approximately
mm millimeter
API American Petroleum Institute
MPa megapascal
ARB Air Resources Board
mV millivolt
ATDC after top dead center
N newton
BTDC before top dead center
N·m newton meter
°C degree Celsius
No. number
CARB California Air Resources Board
O.D. outside diameter
CCA cold cranking amp
oz ounce
cm centimeter
PS horsepower (metric)
cm³ cubic centimeter
psi pound per square inch
cm³/min cubic centimeter per minute
qt quart (U.S.)
cu in cubic inch
RPM revolutions per minute
DC direct current
SAE Society of Automotive Engineers
DI direct injection
sec. second
DVA direct volt adapter
t short ton 2000lb
EPA Environmental Protection Agency
TBN Total Base Number
ESG electronic speed governor
TDC top dead center
°F degree Fahrenheit
V volt
fl oz fluid ounce (U.S.)
VAC volt alternating current
fl oz/min fluid ounce (U.S.) per minute
VDC volt direct current
ft foot
W watt
ft lb foot pound
ft lbf/min foot pound force per minute Symbols
g gram
gal/hr gallon (U.S.) per hour ° angular degree
gal gallon (U.S.) + plus
GL gear lubricant - minus
hp horsepower (U.S.) ± plus or minus
hrs hours Ω ohm
I.D. inside diameter µ micro
IDI indirect injection % percent
in inch ~ approximate
in lb inch pound
JASO Japanese Automobile Standards
Organization
kg kilogram

UNIT CONVERSIONS Units of Torque
Unit Prefixes ft lb x 1.3558 = N·m

ft lb x 0.1383 = kgm
Prefix Symbol Power in lb x 0.1130 = N-m
mega M x 1,000,000 in lb x 0.0115 = kgm
kilo k x 1,000 kgm x 7.2330 = ft lb
centi c x 0.01 kgm x 86.8000 = in lb
milli m x 0.001 kgm x 9.8070 = N·m
micro µ x 0.000001 N·m x 0.7376 = ft lb
N·m x 8.8510 = in lb
Units of Length N·m x 0.1020 = kgm
mile x 1.6090 = km Units of Pressure

ft x 0.3050 =m
in x 2.5400 = cm psi x 0.0689 = bar
in x 25.4000 = mm psi x 6.8950 = kPa
km x 0.6210 = mile psi x 0.0703 = kg/cm²
m x 3.2810 = ft bar x 14.5030 = psi
cm x 0.3940 = in bar x 100.0000 = kPa
mm x 0.0394 = in bar x 29.5300 = in Hg
(60°F)
Units of Volume kPa x 0.1450 = psi
kPa x 0.0100 = bar
gal (U.S.) x 3.78540 =L kPa x 0.0102 = kg/cm²
qt (U.S.) x 0.94635 =L kg/cm² x 98.0700 = psi
cu in x 0.01639 =L kg/cm² x 0.9807 = bar
cu in x 16.38700 = mL kg/cm² x 14.2200 = kPa
fl oz (U.S.) x 0.02957 =L in Hg (60°) x 0.0333 = bar
fl oz (U.S.) x 29.57000 = mL in Hg (60°) x 3.3770 = kPa
cm³ x 1.00000 = mL in Hg (60°) x 0.0344 = kg/cm²
cm³ x 0.03382 = fl oz (U.S.)
Units of Power
Units of Mass
hp (metric or x 0.9863201 = hp SAE
lb x 0.45360 = kg PS)
oz x 28.35000 =g hp (metric or x 0.7354988 = kW
kg x 2.20500 = lb PS)
g x 0.03527 = oz hp SAE x 1.0138697 = hp (metric
or PS)
Units of Force hp SAE x 0.7456999 = kW
kW x 1.3596216 = hp (metric
lbf x 4.4480 =N
or PS)
lbf x 0.4536 = kgf
kW x 1.3410221 = hp SAE
N x 0.2248 = lbf
N x 0.1020 = kgf Units of Temperature
kgf x 2.2050 = lbf
kgf x 9.8070 =N °F = (1.8 · °C) + 32
°C = 0.556 · (°F - 32)


Section 5
PERIODIC
MAINTENANCE
TNE Service Manual
Table of Contents
Page
Precautions ................................................................................... 5-16
The Importance of Periodic Maintenance................................ 5-16
Performing Periodic Maintenance ........................................... 5-16
Yanmar Replacement Parts .................................................... 5-16
Required EPA / ARB Maintenance - USA Only....................... 5-16
EPA / ARB Installation Requirements - USA Only .................. 5-16
Tightening Fasteners............................................................... 5-16
Standard Torque Chart.................................................................. 5-17
Periodic Maintenance Schedule.................................................... 5-17
Periodic Maintenance Procedures ................................................ 5-19
Daily......................................................................................... 5-19
Every 250 Hours of Operation ................................................. 5-21
Every 500 Hours of Operation ................................................. 5-26
Every 1000 Hours of Operation ............................................... 5-29

PERIODIC MAINTENANCE

This section of the Service Manual describes the
procedures for proper care and maintenance of the A DANGER
engine.
CAUTION
EXPLOSION HAZARD!
This will result in a spark and may
cause an explosion or fire. Use a
engine or driven machine without proper
hydrometer to check the remaining
training.
battery charge.
• Read and understand this Operation
• If the electrolyte is frozen, slowly warm
Manual before you operate the
the battery before you recharge it.
machine to ensure that you follow safe
operating practices and maintenance • Failure to comply will result in death or
procedures. serious injury.
0000007en
• Machine safety signs and labels are
and maintenance techniques. A DANGER
• See your authorized Yanmar industrial
engine dealer or distributor for
0000002en

• Only use the key switch to start the
engine.
• NEVER jump start the engine. Sparks
caused by jumping the battery to the
starter terminals may cause a fire or
explosion.
serious injury.
0000004en

A DANGER A DANGER

SCALD HAZARD! • Diesel fuel is extremely flammable and
• NEVER remove the radiator cap if the explosive under certain conditions.
engine is hot. Steam and hot engine • Only fill fuel tank with diesel fuel.
coolant will spurt out and seriously Filling fuel tank with gasoline may
burn you. Allow the engine to cool result in a fire.
the radiator cap. • NEVER refuel with engine running.
• Securely tighten the radiator cap after • Wipe up all spills immediately.
you check the radiator. Steam can • Keep sparks, open flames or any other
spurt out during engine operation if form of ignition (match, cigarette,
the cap is loose. static electric source) away when
• ALWAYS check the level of engine fueling / refueling.
coolant by observing the reserve tank. • NEVER overfill the fuel tank.
• Failure to comply will result in death or • Fill fuel tank and store fuel in a
serious injury. well-ventilated area only.
0000002en • Failure to comply will result in death or
serious injury.
0000005en

A DANGER A DANGER

• Before you operate the engine, check • Be sure to place the diesel fuel
for fuel leaks. Replace rubberized fuel container on the ground when
hoses every two years or every 2000 transferring diesel fuel from the pump
hours of engine operation, whichever to the container. Hold the hose nozzle
comes first, even if the engine has firmly against the side of the container
been out of service. Rubberized fuel while filling it. This prevents static
lines tend to dry out and become electricity build-up which could cause
brittle after two years or 2000 hours of sparks and ignite fuel vapors.
engine operation, whichever comes
• NEVER place diesel fuel or other
first.
flammable material such as oil, hay or
• Failure to comply will result in death or dried grass close to the engine during
serious injury. engine operation or shortly after shut
0000015en down.
serious injury.
0000014en
A DANGER

• NEVER use diesel fuel as a cleaning
agent.
serious injury.
0000012en

A DANGER A DANGER

• NEVER remove the fuel cap with • When you remove any fuel system
engine running. component to perform maintenance
• Failure to comply will result in death or (such as changing the fuel filter) place
serious injury. an approved container under the
0000011en
A DANGER flammable and explosive.
component.
CRUSH HAZARD!
• When you need to transport an engine
serious injury.
for repair have a helper assist you
0000009en
attach it to a hoist and load it on a
truck.
• NEVER stand under hoisted engine. If
the hoist mechanism fails, the engine
will fall on you, causing serious injury
or death.
serious injury.
0000008en

A DANGER A WARNING

EXHAUST HAZARD!
• NEVER operate the engine in an
enclosed area such as a garage,
• Place an approved container under the tunnel, underground room, manhole or
air bleed port when you prime the fuel ship’s hold without proper ventilation.
system. Never use a shop rag to catch
• NEVER block windows, vents, or other
the fuel. Wipe up any spills
means of ventilation if the engine is
immediately. ALWAYS close the air
operating in an enclosed area. All
internal combustion engines create
the system.
carbon monoxide gas during
• Wear eye protection. The fuel system operation. Accumulation of this gas
is under pressure and fuel could spray within an enclosure could cause
out when you open the air bleed port. illness or even death.
• If the unit has an electric fuel pump, • Make sure that all connections are
turn the key switch to the ON position tightened to specifications after repair
for 10 to 15 seconds, or until the fuel is made to the exhaust system.
of bubbles, to allow the electric fuel
or serious injury.
pump to prime the system.
0000003en
• If the unit has a mechanical fuel pump,
operate the fuel priming pump several
times until the fuel coming out of the
air bleed port is free of bubbles.
serious injury.
0000006en

A WARNING A WARNING
SEVER HAZARD! BURN HAZARD!

• Keep hands and other body parts • Keep your hands, and other body
away from moving / rotating parts parts, away from hot engine surfaces
such as the cooling fan, flywheel or such as the muffler, exhaust pipe,
PTO shaft. turbocharger (if equipped) and engine
• Wear tight fitting clothing and keep block during operation and shortly
your hair short or tie it back while the after you shut the engine down. These
engine is running. surfaces are extremely hot while the
• Remove all jewelry before you operate seriously burn you.
or service the machine.
• NEVER start the engine in gear. or serious injury.
Sudden movement of the engine
0000015en
and / or machine could cause death or
serious personal injury.
• NEVER operate the engine without the A WARNING
guards in place.
• Before you start the engine make sure
that all bystanders are clear of the
area.
• Keep children and pets away while the
engine is operating.
ALCOHOL AND DRUG HAZARD!
• NEVER operate the engine while you
• Check before starting the engine that
are under the influence of alcohol or
any tools or shop rags used during
drugs.
maintenance have been removed from
the area. • NEVER operate the engine when you
are feeling ill.
or serious injury. • Failure to comply could result in death
0000002en
or serious injury.
0000004en

A WARNING A WARNING
BURN HAZARD!
EXPOSURE HAZARD! • Batteries contain sulfuric acid. NEVER
• Wear personal protective equipment allow battery fluid to come in contact
such as gloves, work shoes, eye and with clothing, skin or eyes. Severe
hearing protection as required by the burns could result. ALWAYS wear
task at hand. safety goggles and protective clothing
when servicing the battery. If contact
• NEVER wear jewelry, unbuttoned
with the skin and / or eyes should
cuffs, ties or loose fitting clothing
occur, flush with a large amount of
when you are working near
moving / rotating parts such as the
treatment.
cooling fan, flywheel or PTO shaft.
• ALWAYS tie long hair back when you
or serious injury.
are working near moving / rotating
0000007en
parts such as a cooling fan, flywheel,
or PTO shaft.
• NEVER operate the engine while A WARNING
wearing a headset to listen to music or
radio because it will be difficult to hear
warning signals.
or serious injury. HIGH PRESSURE HAZARD!
0000005en
• Avoid skin contact with high pressure
system leak such as a broken fuel
or cardboard.
or serious injury.
0000018en

A WARNING A WARNING
BURN HAZARD!
SHOCK HAZARD!
electrical system.
or serious injury.
0000011en
• Failure to comply could result in death A CAUTION
or serious injury.
0000009en
A WARNING
FLYING OBJECT HAZARD!

SEVER HAZARD! compressed air or high-pressure
• Stop the engine before you begin to water. Dust, flying debris, compressed
service it. air, pressurized water or steam may
injure your eyes.
when you are servicing the engine. • Failure to comply may result in minor
Someone may accidentally start the or moderate injury.
engine and not realize you are 0000003en

serious injury.
or serious injury.
0000010en

CAUTION CAUTION
• Only use diesel fuels recommended by • Only use the engine coolant specified.
Yanmar for the best engine Other engine coolants may affect
performance, to prevent engine warranty coverage, cause an internal
damage and to comply with EPA / ARB build up of rust and scale and / or
warranty requirements. shorten engine life.
• Only use clean diesel fuel. • Prevent dirt and debris from
• NEVER remove primary strainer from contaminating engine coolant.
the fuel tank filler port (if equipped). If Carefully clean the radiator cap and
removed, dirt and debris could get into the surrounding area before you
the fuel system causing it to clog. remove the cap.
0000004en • NEVER mix different types of engine
CAUTION
0000006en
• Only use the engine oil specified.
Other engine oils may affect warranty
coverage, cause internal engine CAUTION
components to seize, or shorten • NEVER attempt to modify the engine’s
engine life. design or safety features such as
• Prevent dirt and debris from defeating the engine speed limit
contaminating engine oil. Carefully control or the diesel fuel injection
clean the oil cap / dipstick and the quantity control.
surrounding area before you remove • Modifications may impair the engine’s
the cap. safety and performance
• NEVER mix different types of engine characteristics and shorten the
oil. This may adversely affect the engine’s life. Any alterations to this
lubricating properties of the engine oil. engine may void its warranty. Be sure
to use Yanmar genuine replacement
• NEVER overfill. Overfilling may result parts.
in white exhaust smoke, engine 0000079en
overspeed or internal damage.
0000005en

CAUTION CAUTION
Observe the following environmental Observe the following environmental
operating conditions to maintain engine operating conditions to maintain engine
performance and avoid premature performance and avoid premature
engine wear: engine wear:
• Avoid operating in extremely dusty • NEVER run the engine if the ambient
conditions. temperature is above +113°F (+45°C)
• Avoid operating in the presence of or below +5°F (-15°C).
chemical gases or fumes. ◆ If the ambient temperature exceeds
• Avoid operating in a corrosive +113°F (+45°C) the engine may
atmosphere such as salt water spray. overheat and cause the engine oil to
break down.
• NEVER install the engine in a ◆ If the ambient temperature falls
floodplain unless proper precautions below +5°F (-15°C) rubber
are taken to avoid being subject to a components such as gaskets and
flood. seals will harden causing premature
• NEVER expose the engine to the rain. engine wear and damage.
0000003enTNE
◆ Contact your authorized Yanmar
industrial engine dealer or
distributor if the engine will be
operated in either temperature
extreme.
• Contact your authorized Yanmar
industrial engine dealer or distributor
if you need to operate the engine at
high altitudes. At high altitudes the
engine will lose power, run rough, and
produce exhaust gases that exceed
the design specifications.
0000065en
CAUTION
NEVER hold the key in the START
position for longer than 15 seconds or
the starter motor will overheat.
0000007en

CAUTION CAUTION
For maximum engine life, Yanmar New Engine Break In:
recommends that when shutting the • On the initial engine start-up, allow the
engine down, you allow the engine to engine to idle for approximately 15
idle, without load, for 5 minutes. This minutes while you check for proper
will allow the engine components that engine oil pressure, diesel fuel leaks,
operate at high temperatures, such as engine oil leaks, coolant leaks, and for
the turbocharger (if equipped) and proper operation of the indicators
exhaust system, to cool slightly before and / or gauges.
the engine itself is shut down.
0000008en
• During the first hour of operation, vary
the engine speed and load on the
engine. Short periods of maximum
CAUTION engine speed and load are desirable.
NEVER use an engine starting aid such Avoid prolonged operation at
as ether. Engine damage will result. minimum or maximum engine speeds
0000009en and loads for the next 4 to 5 hours.
• During the break-in period, carefully
CAUTION observe the engine oil pressure and
engine temperature.
Make sure the engine is installed on a
level surface. If a continuously running • During the break-in period, check the
engine is installed at an angle greater engine oil and coolant levels
than 20° (in any direction) or if an engine frequently.
runs for short periods of time (less than 0000011en
3 minutes) at an angle greater than 25°

in any direction, engine oil may enter the CAUTION
combustion chamber causing exessive
engine speed and generate white NEVER engage the starter motor while
smoke. This may cause serious engine the engine is running. This may damage
damage. the starter motor pinion and / or ring
gear.
0000010enTNE
0000012en

CAUTION CAUTION
NEVER use high pressure water or
a wire brush to clean the radiator fins.
Radiator fins damage easily.
0000016en
Be environmentally responsible. Follow

these procedures for hazardous waste CAUTION
disposal. Failure to follow these
procedures may seriously harm the NEVER attempt to adjust the low or high
environment. idle speed limit screw. This may impair
• Follow the guidelines of the EPA or machine and shorten its life. If the idle
other governmental agency for the speed limit screws require adjustment,
proper disposal of hazardous see your authorized Yanmar industrial
materials such as engine oil, diesel engine dealer or distributor.
fuel and engine coolant. Consult the 0000017en
local authorities or reclamation facility.
• NEVER dispose of hazardous CAUTION
materials irresponsibly by dumping
them into a sewer, on the ground or If the fuel filter / water separator is
into ground water or waterways. positioned higher than the fuel level in
0000013en
the fuel tank, water may not drip out
when the fuel filter / water separator
drain cock is opened. If this happens,
CAUTION turn the air vent screw on the top of the
Protect the air cleaner, turbocharger (if fuel filter / water separator 2-3 turns
equipped) and electric components counterclockwise.
from damage when you use steam or Be sure to tighten the air vent screw
use high-pressure water to clean the after the water has drained out.
engine. 0000025en
0000014en
CAUTION
CAUTION
• When the engine is operated in dusty
• NEVER overfill the engine with engine conditions, clean the air cleaner
oil. element more frequently.
• ALWAYS keep the oil level between • NEVER operate the engine with the air
upper and lower lines on the dipstick. cleaner or element(s) removed. This
0000015en may cause foreign material to enter the
engine and damage it.
0000026en

CAUTION
The maximum air intake restriction shall
be 0.90 psi (6.23 kPa; 635 mm Aq) or
less. Clean or replace the air cleaner
element if the air intake restriction
exceeds the above mentioned value.
0000046en

PRECAUTIONS Perform periodic maintenance procedures in an

open, level area free from traffic. If possible,
The Importance of Periodic perform the procedures indoors to prevent
environmental conditions, such as rain, wind, or
Maintenance snow, from damaging the machine.
Engine deterioration and wear occurs in proportion
to length of time the engine has been in service and Yanmar Replacement Parts
the conditions the engine is subject to during Yanmar recommends that you use genuine Yanmar
operation. Periodic maintenance prevents parts when replacement parts are needed.
unexpected downtime, reduces the number of Genuine replacement parts help ensure long
accidents due to poor machine performance and engine life.
helps extend the life of the engine.
Required EPA / ARB Maintenance -
Performing Periodic Maintenance
USA Only
A WARNING To maintain optimum engine performance and
compliance with the Environmental Protection
Agency (EPA) Regulations Non-road Engines and
the California Air Resources Board (ARB,
California), it is essential that you follow the
Periodic Maintenance Schedule on page 5-17 and
EXHAUST HAZARD! Periodic Maintenance Procedures which start on
page 5-19.
• NEVER operate the engine in an
enclosed area such as a garage, EPA / ARB Installation Requirements
tunnel, underground room, manhole or - USA Only
ship’s hold without proper ventilation.
The following are the installation requirements for
• NEVER block windows, vents, or other
the EPA / ARB. Unless these requirements are met,
means of ventilation if the engine is
the exhaust gas emissions will not be within the
operating in an enclosed area. All
limits specified by the EPA and ARB.
internal combustion engines create
carbon monoxide gas during Maximum Exhaust Gas Restriction - 3.84 psi
operation. Accumulation of this gas (26.48 kPa; 2700 mm Aq) or less.
within an enclosure could cause
illness or even death. Maximum Air Intake Restriction - 0.90 psi
(6.23kPa; 635mm Aq) or less. Clean or replace the
• Make sure that all connections are air cleaner element if the air intake restriction
tightened to specifications after repair exceeds the above mentioned value.
is made to the exhaust system.
• Failure to comply could result in death Tightening Fasteners
or serious injury. Use the correct amount of torque when you tighten
0000003en fasteners on the machine. Applying excessive
torque may damage the fastener or component and
not enough torque may cause a leak or component
failure.

CAUTION
The tightening torque in the Standard
Torque Chart (page 5-17) should be
applied only to the bolts with a “7” head.
(JIS strength classification: 7T)
• Apply 60% torque to
bolts that are not listed.
• Apply 80% torque when
tightened to aluminum alloy.
0000023enTNESM
STANDARD TORQUE CHART

Thread size × Pitch mm M6×1.0 M8×1.25 M10×1.5 M12×1.75 M14×1.5 M16×1.5
in lbs 96.0 ± 9.0 - - - - -
ft lbs - 19.0 ± 2.0 36.0 ± 4.0 65.0 ± 7.0 101.0 ± 7.0 167.0 ± 7.0
Tightening Torque
N·m 10.8 ± 1.0 25.5 ± 2.9 49.0 ± 4.9 88.3 ± 9.8 137.0 ± 9.8 226.0 ± 9.8
kgf·m 1.1 ± 0.1 2.6 ± 0.3 5.0 ± 0.5 9.0 ± 1.0 14.0 ± 1.5 23.0 ± 2.0
PERIODIC MAINTENANCE CAUTION

SCHEDULE Establish a periodic maintenance plan
Daily and periodic maintenance is important to according to the engine application and
keep the engine in good operating condition. The make sure you perform the required
following is a summary of maintenance items by periodic maintenance at intervals
periodic maintenance intervals. Periodic indicated. Failure to follow these
maintenance intervals vary depending on engine guidelines will impair the engine’s safety
application, loads, diesel fuel and engine oil used and performance characteristics,
and are hard to establish definitively. The following shorten the engine’s life and may affect
should be treated only as a general guideline. the warranty coverage on your engine.
See Yanmar Limited Warranty on
page 2-3.
Consult your authorized Yanmar
industrial engine dealer or distributor for
assistance when checking items marked
with a z.
0000024enTNESM

c: Check : Replace z: Contact your authorized Yanmar industrial engine dealer or distributor
Periodic Maintenance Interval

Check
System Check Item During Daily Every Every Every Every Every
Operation 250 500 1000 2000 4000
hours hours hours hours hours
Cooling Check & Re-fill Engine
System Coolant c
Check Engine Coolant
Temperature Indicator c
Check & Clean Radiator c or every
Fins 1 6 weeks
Check & Adjust Cooling Fan
First Check after 50 hours
c or every
V-belt 6 weeks
Drain, Flush, and Re-fill or every
Cooling System with New 2 yr.
Coolant which-ever
comes first
Cylinder Adjust Intake / Exhaust z or every
Head Valve Clearance 6 months
Electrical Check Battery c or every
Equipment 6 weeks
Check Battery Indicator c
Emission Inspect, Clean & Test Fuel z or every
Control Injectors
Warranty 1 year
Engine Oil Check Engine Oil Level c

Check Engine Oil Pressure
Indicator c
Drain & Fill Engine Oil z or every
3 months
Replace Engine Oil Filter z or every
3 months
Engine Check & Adjust Governor c or every
Speed Lever & Engine Speed
Control Control 3 months
Fuel Check & Re-fill Fuel Tank

Level c
Check Fuel Filter Indicator c
Drain Fuel Filter / Water
Separator c
Check Fuel Filter / Water
Separator c
Clean Fuel Filter / Water c or every
Separator1 6 months
Replace Fuel Filter 1
or every
6 months
Hoses Inspect or Replace Fuel
System & Cooling System c c or every
2 years
Hoses
Intake & Clean or Replace Air c or every or every
Exhaust Cleaner Element1 2 6 weeks 1 year
1 Very dirty conditions will require daily check and cleaning.
2 In dirty or dusty environments, replace at 1000 hours or as needed.
Note: These procedures are considered normal maintenance and are performed at the owner’s expense.

A WARNING
PROCEDURES
Daily
HIGH PRESSURE HAZARD!
Perform the following procedures daily.
• Avoid skin contact with high pressure
• Drain Fuel Filter / Water Separator diesel fuel spray caused by a fuel
• Check Fuel Hoses and Engine Coolant Hoses system leak such as a broken fuel
Drain Fuel Filter / Water Separator penetrate your skin and result in
A DANGER high pressure fuel spray obtain
Yanmar industrial engine dealer or
FIRE AND EXPLOSION HAZARD! distributor repair the damage.
or serious injury.
• When you remove any fuel system 0000008en
component to perform maintenance
(such as changing the fuel filter) place
an approved container under the CAUTION
opening to catch the fuel. If the fuel filter / water separator is
positioned higher than the fuel level in
the fuel tank, water may not drip out
when the fuel filter / water separator
drain cock is opened. If this happens,
• Wipe up any spills immediately. turn the air vent screw on the top of the
• Wear eye protection. The fuel system fuel filter / water separator 2-3 turns
is under pressure and fuel could spray counterclockwise.
out when you remove any fuel system Be sure to tighten the air vent screw
component. after the water has drained out.
• Failure to comply will result in death or 0000025en
serious injury.
0000009en

1. Position an approved container under the fuel
CAUTION filter / water separator (Figure 5-1, (1)) to
collect the contaminants.
2. Loosen the drain cock (Figure 5-1, (2)) at the
bottom of the fuel filter / water separator. Drain
any water collected inside.
3. Hand tighten the drain cock.
these procedures for hazardous waste 4. Be sure to prime the diesel fuel system when
disposal. Failure to follow these you are done. See Priming the Fuel System on
procedures may seriously harm the page 4-12.
environment.
Check Fuel Hoses and Engine Coolant
• Follow the guidelines of the EPA or Hoses
other governmental agency for the
Daily check the fuel system and engine coolant
proper disposal of hazardous
system hoses. If they are cracked or degraded,
replace them.
• NEVER dispose of hazardous
into ground water or waterways.
0000013en
NEVER wait until the scheduled periodic

maintenance if the fuel filter indicator comes on.
The fuel filter / water separator contains a sensor to
detect the amount of water and contaminants. This
sensor sends a signal to an indicator to alert the
operator.
Drain the fuel filter / water separator as follows:
(1)
(2) 0000862C
Figure 5-1

• If there is a large amount of contamination on
Every 250 Hours of Operation the fins, apply detergent, thoroughly clean and
rinse with tap water.
Perform the following maintenance every 250 hours
of operation. CAUTION
• Check and Clean Radiator Fins NEVER use high pressure water or
• Check and Adjust Cooling Fan V-Belt a wire brush to clean the radiator fins.
• Check Battery Radiator fins damage easily.
0000016en
• Clean Air Cleaner Element
Check and Clean Radiator Fins
A CAUTION FULL
(1)
LOW
FLYING OBJECT HAZARD! 0000085A

Figure 5-2
injure your eyes.
• Failure to comply may result in minor
or moderate injury.
0000003en
Dirt and dust adhering to the radiator fins reduce

the cooling performance, causing overheating.
Make it a rule to check the radiator fins daily and
clean as needed.
Note that a typical radiator is shown in Figure 5-2
for illustrative purposes only.
• Blow off dirt and dust from fins and radiator with
28 psi (0.19MPa, 2kgf/cm2) or less of
compressed air (Figure 5-2, (1)). Be careful
not to damage the fins with the compressed air.

Check and Adjust Cooling Fan V-belt 2. If necessary, adjust the V-belt tension. Loosen
The V-belt will slip if it does not have the proper the set bolt (Figure 5-4, (1)) and move the
tension. This will prevent the alternator from alternator (Figure 5-4, (2)) with a pry bar
generating sufficient power. Also, the engine will (Figure 5-4, (3)) to tighten the V-belt.
overheat due to the engine coolant pump pulley
slipping. Be sure to check for proper belt tension
after the first 50 hours of operation. Thereafter,
(3)
check the belt tension every 250 hours of
operation.
Check and adjust the V-belt tension (deflection) as
follows:
1. Press the V-belt down with your thumb with a (1)
force of approximately 22 ft lbs (98 N•m,
(2)
10 kgf•m) to check the deflection.
There are three positions to check for V-belt
tension (Figure 5-3, (A), (B) and (C)). You can
check the tension at whichever position is the
most accessible. The proper deflection of a used
V-belt at each position is: 0001553A
Figure 5-4
Used V-belt Tension
3. Check the V-belt for cracks, oil or wear. If any of
A B C
these conditions exist, replace the V-belt.
3/8 ~1/2 in 1/4 ~3/8 in 5/16 ~1/2 in
(10~14 mm) (7~10 mm) (9~13 mm) • “New V-belt” refers to a V-belt which has been
used less than 5 minutes on a running engine.
• “Used V-belt” refers to a V-belt which has been
(A)
used on a running engine for 5 minutes or
more.
4. Inspect the condition of the used V-belt. There
must be clearance (Figure 5-5, (1)) between
the V-belt and the bottom of the pulley groove. If
there is no clearance (Figure 5-5, (2)) between
the V-belt and the bottom of the pulley groove,
replace the V-belt.
(B)
(C)
(2)
(1)
0001111A
0000584
Figure 5-3 Figure 5-5

5. Install the new V-belt. Refer to the table for
proper tension. A WARNING
New V-belt Tension
A B C
5/16 ~7/16 in 3/16 ~5/16 in 1/4 ~7/16 in
(8~12 mm) (5~8 mm) (7~11 mm)
BURN HAZARD!
6. After adjusting, run the engine for 5 minutes or • Batteries contain sulfuric acid. NEVER
more. Check the tension again using the allow battery fluid to come in contact
specifications for a used V-belt. with clothing, skin or eyes. Severe
burns could result. ALWAYS wear
Used V-belt Tension safety goggles and protective clothing
A B C when servicing the battery. If contact
3/8 ~1/2 in 1/4 ~3/8 in 5/16 ~1/2 in with the skin and / or eyes should
(10~14 mm) (7~10 mm) (9~13 mm) occur, flush with a large amount of
Check Battery treatment.
A DANGER or serious injury.
0000007en
CAUTION
EXPLOSION HAZARD!
This will result in a spark and may Be environmentally responsible. Follow
cause an explosion or fire. Use a these procedures for hazardous waste
hydrometer to check the remaining disposal. Failure to follow these
battery charge. procedures may seriously harm the
• If the electrolyte is frozen, slowly warm environment.
the battery before you recharge it. • Follow the guidelines of the EPA or
• Failure to comply will result in death or other governmental agency for the
serious injury. proper disposal of hazardous
0000007en materials such as engine oil, diesel
0000013en

Clean Air Cleaner Element
(3) Note that a typical air cleaner is shown in
Figure 5-7 and Figure 5-8 for illustrative purposes
(2)
only.
The engine performance is adversely affected
(1) when the air cleaner element is clogged with dust.
Be sure to clean the air filter element periodically.
1. Unlatch and remove the air cleaner cover
(Figure 5-7, (1)).
0000067A
2. Remove the element (Figure 5-7, (2)) (outer
Figure 5-6 element if equipped with two elements).
• When the amount of fluid nears the lower limit
(Figure 5-6, (1)), fill with distilled water A CAUTION
(Figure 5-6, (2)) so it is at the upper limit
(Figure 5-6, (3)). If operation continues with
insufficient battery fluid, the battery life is
shortened, and the battery may overheat and
explode. During the summer, check the fluid
level more often than specified.
• If the engine cranking speed is so slow that the FLYING OBJECT HAZARD!
engine does not start, recharge the battery. • ALWAYS wear eye protection when
• If the engine still will not start after charging, servicing engine and when using
have your authorized Yanmar industrial engine compressed air or high-pressure
dealer or distributor check the battery and the water. Dust, flying debris, compressed
engine’s starting system. air, pressurized water or steam may
• If operating the machine where the ambient injure your eyes.
temperature could drop to 5°F (-15°C) or less, • Failure to comply may result in minor
remove the battery from the machine at the end or moderate injury.
of the day. Store the battery in a warm place 0000003en
until the next use. This will help start the engine
easily at low ambient temperatures.

3. Blow air (Figure 5-7, (3)) through the element 6. Install the element into the air cleaner case
from the inside out using 42–71 psi (Figure 5-7, (4)).
(0.29−0.49MPa, 3.0−5.0kgf/cm2) compressed 7. Install the air cleaner cover making sure you
air to remove the particulates. Use the lowest match the arrow (Figure 5-7, (5)) on the cover
possible air pressure to remove the dust without with the arrow on the case (Figure 5-7, (6)).
damaging the element.
8. Latch the air cleaner cover to the case.
If the air cleaner is equipped with a double
element, only remove and replace the inner
CAUTION
element (Figure 5-8, (1)) if the engine lacks
power or the dust indicator actuates (if • When the engine is operated in dusty
equipped). This is in addition to replacing the conditions, clean the air cleaner
outer element. element more frequently.
• NEVER operate the engine with the air
The inner element should not be removed when
cleaner or element(s) removed. This
cleaning or replacing the outer element. The
may cause foreign material to enter the
inner element is used to prevent dust from
engine and damage it.
entering the engine while servicing the outer
0000026en
element.
(6) (4)
(2)
(5)
(3)
(1)
0000070A
Figure 5-7
(1)
0000071A
Figure 5-8
4. Replace the element with a new one if the
element is damaged, excessively dirty or oily.
5. Clean inside of the air cleaner cover.

Every 500 Hours of Operation CAUTION

Perform the following maintenance every 500 hours Other engine oils may affect warranty
of operation. coverage, cause internal engine
• Replace Engine Oil and Engine Oil Filter
engine life.
• Check and Adjust the Governor Lever and • Prevent dirt and debris from
Engine Speed Control contaminating engine oil. Carefully
clean the oil cap / dipstick and the
Replace Engine Oil and Engine Oil surrounding area before you remove
Filter the cap.
A WARNING oil. This may adversely affect the
• NEVER overfill. Overfilling may result
in white exhaust smoke, engine
BURN HAZARD! 0000005en

is still hot, stay clear of the hot engine CAUTION
or serious injury.
0000011en
these procedures for hazardous waste
disposal. Failure to follow these
environment.
0000013en

Change the engine oil every 500 hours of Remove the engine oil filter as follows:
operation. Replace the engine oil filter at the same
time. 1. Turn the engine oil filter (Figure 5-11, (1))
counterclockwise (Figure 5-11, (2)) using a
Drain the engine oil as follows: filter wrench.
1. Make sure the engine is level.
2. Start the engine and bring it up to operating
temperature.
3. Stop the engine.
4. Remove the oil filler cap (Figure 5-9, (1)) to (2)
vent the engine crankcase and to allow the
engine oil to drain more easily.
5. Position a container (Figure 5-10, (1)) under
the engine to collect waste oil. (1)
(1)
0001109
Figure 5-10
(1)
(3)
(2)
(1)
0001108B
Figure 5-9
0001110A
6. Remove the drain plug (Figure 5-10, (2)). Allow
oil to drain. Figure 5-11
After all oil has been drained from the engine, 2. Clean the engine oil filter mounting face.
install the drain plug (Figure 5-10, (2)) and 3. Lightly coat the gasket on the new oil filter with
tighten to 14-17 ft lbs (19.6-23.5 N•m, 2.0-2.4 engine oil. Install the new engine oil filter
kgf•m). manually by turning it clockwise
7. Dispose of used oil properly. (Figure 5-11, (3)) until it contacts the mounting
surface. Tighten an additional 3/4 of a turn
using the filter wrench.

Applicable Engine Oil Filter Part No. CAUTION

(Figure 5-11, (1))
NEVER remove or attempt to remove the
4TNE92-NMH tamper-proof devices from the full-load
4TNE92-NMHA 129150-35152 fuel adjusting screw or the high-speed
4TNE98-NMH throttle limit screw on the fuel injection
pump and governor assembly. These
4. Add new engine oil to the engine as specified in adjustments have been made at the
Adding Engine Oil on page 4-15. factory to meet all applicable emissions
regulations and then sealed.
Check and Adjust the Governor Lever
and Engine Speed Control NEVER attempt to make any
adjustments to these sealed adjustment
The governor lever and engine speed control
screws. If adjustments are required, they
(accelerator lever, pedal, etc.) of the machine are
can be made only by a qualified fuel
connected together by an accelerator cable or rod.
injection shop that will ensure the
If the cable becomes stretched, or the connections
injection pump continues to meet all
loosen, the governor lever may not respond to
applicable emissions regulations and
change of engine speed control position. This may
then replace the tamper-proof seals.
make operation of the machine unsafe. Check the
0000146en
cable periodically and adjust if necessary. Consult
your authorized Yanmar industrial engine dealer or
distributor for the adjustment procedure. (2)
(1)
NEVER force the accelerator cable or pedal to
move. This may deform the governor lever or
stretch the cable and cause irregular operation of
the engine speed control.
Checking and adjusting the governor lever:
1. Check that the governor lever (Figure 5-12, (1)) (3)
makes uniform contact with the low idle
(Figure 5-12, (2)) and high idle
0001106A
(Figure 5-12, (3)) speed limit screws when the
engine speed control is in the high idle speed or Figure 5-12
low idle speed position.
2. If the governor lever does not make contact with
the high idle or low idle speed limit screw, adjust
the accelerator cable.
3. In some engine speed control applications,
loosen the accelerator cable locknut and adjust
the cable so the governor lever makes proper
contact with the high / low idle speed limit
screw.

Clean Fuel Filter / Water Separator
Every 1000 Hours of Operation
A DANGER
Perform the following maintenance every 1000
hours of operation.
• Adjust Intake / Exhaust Valve Clearance
• Clean Fuel / Water Separator
• Replace Fuel Filter • Diesel fuel is extremely flammable and
Adjust Intake / Exhaust Valve
Clearance • When you remove any fuel system
component to perform maintenance
Proper adjustment is necessary to maintain the (such as changing the fuel filter) place
correct timing for opening and closing the valves. an approved container under the
Improper adjustment will cause the engine to run opening to catch the fuel.
noisily, resulting in poor engine performance and
engine damage. See Measuring and Adjusting • NEVER use a shop rag to catch the
Valve Clearance on page 6-32. fuel. Vapors from the rag are extremely
component.
serious injury.
0000009en

CAUTION (5) (9)
(2)
(10)
(3) (6)
disposal. Failure to follow these (8)
procedures may seriously harm the (1)
environment. (4)
0000013en
(7)
0000073A
Figure 5-13
Periodically clean the fuel filter / water separator
element and inside cup. 6. Remove the float ring (Figure 5-13, (8)) from
the cup. Pour the contaminants into the
1. Position an approved container under the cup
container and dispose it properly.
(Figure 5-13, (1)) of the fuel filter / water
separator to collect the contaminants. 7. Clean the element (Figure 5-13, (9)) and inside
cup. Replace the element if it is damaged.
2. Close (Figure 5-13, (2)) the fuel cock
(Figure 5-13, (3)). Applicable Element Part No.(Figure 5-13, (9))
3. Loosen the drain cock (Figure 5-13, (4)) and 4TNE92-NMH
drain the contaminants. See Drain Fuel Filter / 4TNE92-NMHA 119802-55710
Water Separator on page 5-19. 4TNE98-NMH
4. Turn the retaining ring (Figure 5-13, (5)) to the
left (Figure 5-13, (10)) and remove the cup 8. Install the element and O-ring in the bracket.
(Figure 5-13, (6)). If equipped, disconnect the 9. Position the float ring in the cup.
sensor wire (Figure 5-13, (7)) from the cup
10. Check the O-ring on the cup. Replace if
before removing the cup.
necessary.
5. Carefully hold the cup to prevent fuel from 11. Install the cup to the bracket by tightening the
spilling. If you spill any fuel, clean up the spill retaining ring to the right (Figure 5-13, (6)) to a
completely. torque of 11-15 ft lbs (15-20 N•m, 1.5-2.0
kgf•m).

12. Close the drain cock. Reconnect the sensor
wire if equipped. A WARNING
13. Open the fuel cock (Figure 5-13, (3)).
14. Prime the fuel system. See Priming The Fuel
System on page 4-13.
15. Check for leaks.
Replace Fuel Filter • Avoid skin contact with high pressure
A DANGER system leak such as a broken fuel
• Diesel fuel is extremely flammable and hands. ALWAYS use a piece of wood
explosive under certain conditions. or cardboard. Have your authorized
• When you remove any fuel system Yanmar industrial engine dealer or
component to perform maintenance distributor repair the damage.
(such as changing the fuel filter) place • Failure to comply could result in death
an approved container under the or serious injury.
0000008en
component.
serious injury.
0000009en

CAUTION
(2)
(3) (4)
(1)
disposal. Failure to follow these 0000862D

Figure 5-14
environment.
• Follow the guidelines of the EPA or 4. Place an approved container under fuel filter.
other governmental agency for the 5. Carefully open the drain plug (Figure 5-15, (1))
proper disposal of hazardous to drain fuel from the fuel filter.
materials such as engine oil, diesel 6. Remove the fuel filter (Figure 5-14, (2)) by
fuel and engine coolant. Consult the turning it to the left (Figure 5-14, (3)). Wipe up
local authorities or reclamation facility. all spilled fuel.
• NEVER dispose of hazardous 7. Remove the drain plug (Figure 5-15, (1)) from
materials irresponsibly by dumping the fuel filter (Figure 5-15, (2)) by turning it to
them into a sewer, on the ground or the left (Figure 5-15, (3)).
8. Check the condition of the drain plug O-ring
0000013en
(Figure 5-15, (4)). Replace the O-ring if
damaged.
CAUTION
For maximum engine life, Yanmar
(10)
recommends that when shutting the
engine down, you allow the engine to (8)
idle, without load, for 5 minutes. This
will allow the engine components that (7)
operate at high temperatures, such as (2)
the turbocharger (if equipped) and
exhaust system, to cool slightly before
the engine itself is shut down. (6)
0000008en
(5)
Replace the fuel filter at specified intervals to (4)

prevent contaminants from adversely affecting the
diesel fuel flow. (1)
1. Stop the engine and allow it to cool. (3) (9)

2. Close all fuel cocks in fuel line. 0000863B
3. Disconnect the fuel filter sensor connector Figure 5-15

(Figure 5-14, (1)).
9. Set the drain plug aside for reinstallation.

10. Remove the fuel filter sensor assembly Applicable In-Line Fuel Filter Part No.
(Figure 5-15, (5)) by turning it to the left (Figure 5-15, (7))
(Figure 5-15, (3)).
4TNE92-NMH
11. Carefully remove the in-line fuel filter 4TNE92-NMHA 129901-55860
(Figure 5-15, (7)) from the output nipple 4TNE98-NMH
(Figure 5-15, (8)) that goes to the fuel injection
pump.
12. Dispose of the fuel, fuel filters and O-ring (if
replaced) properly. Follow the guidelines of the
EPA or other government agency.
13. Carefully install the new in-line fuel filter
(Figure 5-15, (7)) into the output nipple
(Figure 5-15, (8)).
14. Carefully install the fuel filter sensor assembly
(Figure 5-15, (5)) in the new fuel filter using the
new O-ring supplied with the fuel filter
(Figure 5-15, (2)) by turning the fuel filter
sensor assembly to the right (Figure 5-15, (9)).
15. Install the drain plug (Figure 5-15, (1)) on the
new fuel filter (Figure 5-15, (3)) by turning the
drain plug to the right (Figure 5-15, (8)). Hand
tighten only.
16. Clean the fuel filter mounting surface
(Figure 5-15, (10)) and apply a small amount of
diesel fuel to the gasket of the new filter.
17. Install the new fuel filter (Figure 5-14, (2)) by
turning it to the right (Figure 5-14, (4)) until it
contacts the mounting surface. Tighten one
additional turn.
18. Open all fuel cocks in the fuel line.
19. Reconnect the fuel filter sensor connector
(Figure 5-14, (1)).
20. Prime the fuel system. See Priming the Fuel
System on page 4-12.
21. Check for fuel leaks.
Applicable Fuel Filter Part No.

(Figure 5-14, (2))
4TNE92-NMH
4TNE92-NMHA 129901-55850
4TNE98-NMH

Inspect Clean and Test Fuel Injectors
=
Every 2000 Hours of Operation

A WARNING
Perform the following maintenance every 2000
hours of operation.
• Replace Air Cleaner Element
• Inspect Clean and Test Fuel Injectors
Replace Air Cleaner Element • Avoid skin contact with high pressure
CAUTION system leak such as a broken fuel
The maximum air intake restriction shall injection line. High pressure fuel can
be 0.90 psi (6.23 kPa; 635 mm Aq) or penetrate your skin and result in
less. Clean or replace the air cleaner serious injury. If you are exposed to
element if the air intake restriction high pressure fuel spray obtain
exceeds the above mentioned value. prompt medical treatment.
0000046en • NEVER check for a fuel leak with your
Replace the air cleaner element (Figure 5-7, (2)) Yanmar industrial engine dealer or
every 2000 hours even if it is not damaged or dirty. distributor repair the damage.
When replacing the element, clean the inside of the • Failure to comply could result in death
air cleaner case (Figure 5-7, (4)). or serious injury.
0000008en
If the air cleaner is equipped with a double element,
only remove and replace the inner element Proper operation of the fuel injectors is required to
(Figure 5-8, (1)) if the engine lacks power or the obtain the optimum injection pattern for full engine
dust indicator actuates (if equipped). This is in performance. The EPA / ARB requires that you
addition to replacing the outer element. have the injectors inspected, cleaned and tested
every 2000 hours. See Servicing the Fuel
Injectors on page 7-35.

Every 4000 Hours of Operation A CAUTION

• Drain, Flush, and Re-fill the Coolant System
with New Coolant
• Replace Fuel Hoses and Engine Coolant
Hoses
COOLANT HAZARD!
Drain, Flush, and Re-fill the Coolant
System with New Coolant • Wear eye protection and rubber gloves
when you handle Long Life or
Extended Life engine coolant. If
A DANGER contact with the eyes or skin should
occur, wash immediately with clean
water.
or moderate injury.
0000005en
SCALD HAZARD!
• NEVER remove the radiator cap if the CAUTION
coolant will spurt out and seriously
burn you. Allow the engine to cool
the radiator cap.
• Securely tighten the radiator cap after Be environmentally responsible. Follow
you check the radiator. Steam can these procedures for hazardous waste
spurt out during engine operation if disposal. Failure to follow these
the cap is loose. procedures may seriously harm the
• ALWAYS check the level of engine environment.
coolant by observing the reserve tank. • Follow the guidelines of the EPA or
• Failure to comply will result in death or other governmental agency for the
serious injury. proper disposal of hazardous
0000002en
0000013en

Engine coolant contaminated with rust or scale 4. After draining the engine coolant, flush the
reduces the cooling effect. Even when extended life radiator and engine block to remove any rust,
engine coolant is properly mixed, the engine scale and contaminants. Then reinstall and
coolant gets contaminated as its ingredients tighten the drain plug or close the drain cock in
deteriorate. Drain, flush and re-fill the cooling the radiator. Reinstall and tighten the engine
system with new coolant every 4000 hours or once block drain plug.
every 2 years, whichever comes first. 5. Fill radiator and engine with engine coolant.
1. Remove the radiator cap (Figure 5-16, (1)). See Filling Radiator With Engine Coolant on
page. 4-17.
2. Remove the drain plug or open the drain cock
(Figure 5-16, (2)) at the lower portion of the Replace Fuel Hoses and Engine
radiator and drain the engine coolant. Coolant Hoses
Replace the fuel and engine coolant hoses at least
every two years.
(1)
FULL
LOW
(2) 0000074A
Figure 5-16
3. Remove the coolant drain plug
(Figure 5-17, (1)) from the engine block.
(1)
0001578A
Figure 5-17

Section 6
ENGINE
TNE Service Manual
Table of Contents
Page
Engine Service Information ............................................................. 6-5
Engine Body .............................................................................. 6-5
Gear Train and Camshaft .......................................................... 6-7
Engine Special Torque Chart ........................................................ 6-12
Special Service Tools.................................................................... 6-13
Measuring Instruments.................................................................. 6-15
Before You Begin Servicing..................................................... 6-18
Removal of Engine ........................................................................ 6-19
Cylinder Head Components .................................................... 6-20
Disassembly of Cylinder Head ................................................ 6-21
Cleaning of Cylinder Head Components ................................. 6-25
Inspection of Cylinder Head Components ............................... 6-25
Assembly of Cylinder Head ..................................................... 6-28
Measuring and Adjusting Valve Clearance ................................... 6-32
Valve Clearance Measurement ............................................... 6-32
Valve Clearance Adjustment ................................................... 6-33
Drive Train and Camshaft Components ........................................ 6-34
Disassembly of Drive Train and Camshaft Components......... 6-35
Inspection of Drive Train and Camshaft Components............. 6-40
Honing and Boring................................................................... 6-48
Assembly of Drive Train and Camshaft Components.............. 6-49

ENGINE

ENGINE
servicing of the engine. A CAUTION
A WARNING

SEVER HAZARD! • ALWAYS wear eye protection when
• Stop the engine before you begin to servicing engine and when using
service it. compressed air or high-pressure
• NEVER leave the key in the key switch water. Dust, flying debris, compressed
when you are servicing the engine. air, pressurized water or steam may
Someone may accidentally start the injure your eyes.
engine and not realize you are • Failure to comply may result in minor
servicing it. This could result in a or moderate injury.
serious injury. 0000003en

is operating, remove all jewelry, tie CAUTION
coverage, cause internal engine
• Failure to comply could result in death components to seize, or shorten
or serious injury. engine life.
0000010en
contaminating engine oil. Carefully
A WARNING clean the oil cap / dipstick and the
the cap.
oil. This may adversely affect the
EXPOSURE HAZARD! in white exhaust smoke, engine
• Always read and follow safety related overspeed or internal damage.
precautions found on containers of 0000005en
hazardous substances like parts
cleaners, primers, sealants, and
sealant removers.
or serious injury.
0000014en

ENGINE
CAUTION
• Only use the engine coolant specified.
Other engine coolants may affect
build up of rust and scale and / or
shorten engine life.
Carefully clean the radiator cap and
remove the cap.
0000006en

ENGINE
ENGINE SERVICE INFORMATION

Engine Body
Cylinder Head
Reference
Page
See
Inspection of
0.0020 in (0.05 mm) 0.0059 in (0.15
Combustion Surface Distortion (Flatness) Cylinder
or less mm)
Head on
page 6-26
0.020 - 0.028 in 0.039 in
Intake See
(0.5 - 0.7 mm) (1.0 mm)
Valve Sink Inspection of
0.024 - 0.032 in 0.043 in Intake and
Exhaust
(0.6 - 0.8 mm) (1.1 mm) Exhaust
Intake 120° - Valves on
Valve Seat Angle page 6-26
Exhaust 90° -
Intake / Exhaust Valve and Guide

Reference
Inspection item Standard Limit
Page
0.3156 - 0.3161 in 0.3189 in
Guide Inside Diameter
(8.015 - 8.030 mm) (8.10 mm)
Valve Stem Outside 0.3136 - 0.3142 in 0.3110 in
Intake Valve
Diameter (7.965 - 7.980 mm) (7.90 mm)
See
0.0014 - 0.0026 in 0.0071 in Inspection of
Oil Clearance
(0.035 - 0.065 mm) (0.18 mm) Intake and
0.3156 - 0.3161 in 0.3189 in Exhaust
Guide Inside Diameter Valves on
(8.015 - 8.030 mm) (8.10 mm)
page 6-26
Valve Stem Outside 0.3136 - 0.3138 in 0.3110 in
Exhaust Valve
Diameter (7.965 - 7.970 mm) (7.90 mm)
0.0018 - 0.0030 in 0.0071 in
Oil Clearance
(0.045 - 0.075 mm) (0.18 mm)
See
Assembly of
0.58 - 0.60 in
Valve Guide Projection From Cylinder Head - Valve
(14.7 - 15.0 mm)
Guides on
page 6-28
See
Assembly of
0.66 - 0.70 in
Valve Seal Projection from Cylinder head - Valve
(16.7 - 17.0 mm)
Guides on
page 6-28

ENGINE
Valve Spring
Reference
Page
1.87 in See
Free Length -
(47.5 mm) Inspection of
Valve
0.05 in Springs on
Squareness -
(1.2 mm) page 6-28
Rocker Arm and Shaft

Reference
Page
0.7283 - 0.7291 in 0.7311 in
Arm Shaft Inside Diameter See
(18.50 - 18.52 mm) (18.57 mm)
Inspection of
0.7272 - 0.7280 in 0.7252 in
Shaft Outside Diameter Rocker Arm
(18.47 - 18.49 mm) (18.42 mm)
Assembly on
0.0004 - 0.0020 in 0.0059 in page 6-26
Oil Clearance
(0.01 - 0.05 mm) (0.15 mm)
Push Rod
Reference
Page
See
Inspection of
0.0012 in
Push Rod Straightness - Push
(0.03 mm)
Rods on
page 6-25

ENGINE
Gear Train and Camshaft
Camshaft
Reference
Page
See Removal
0.0020 - 0.0079 in 0.0118 in of
Side Gap
(0.05 - 0.20 mm) (0.30 mm) Camshaft on
page 6-39
0 - 0.0008 in 0.0020 in
Bending (1/2 the Dial Gauge Reading)
(0 - 0.02 mm) (0.05 mm)
1.6707 - 1.6758 in 1.6608 in
Cam Height
(42.435 - 42.565 mm) (42.185 mm)
1.9681 - 1.9707 in 1.9736 in
Bushing Inside Diameter
(49.990 - 50.055 mm) (50.130 mm)
1.9656 - 1.9665 in 1.9642 in
Gear End Camshaft Outside Diameter
(49.925 - 49.950 mm) (49.890 mm)
0.0016 - 0.0051 in 0.0094 in
Oil Clearance
(0.04 - 0.130 mm) (0.240 mm) See
(50.000 - 50.025 mm) (50.100 mm) Camshaft on
Camshaft Oil 1.9650 - 1.9659 in 1.9636 in page 6-46
Intermediate Camshaft Outside Diameter
Clearance (49.910 - 49.935 mm) (49.875 mm)
0.0026 - 0.0045 in 0.0089 in
Oil Clearance
(0.065 - 0.115 mm) (0.225 mm)
1.9685 - 1.9695 in 1.9724 in
(50.000 - 50.025 mm) (50.100 mm)
1.9656 - 1.9665 in 1.9642 in
Flywheel End Camshaft Outside Diameter
(49.925 - 49.950 mm) (49.890 mm)
0.0020 - 0.0039 in 0.0083 in
Oil Clearance
(0.050 - 0.100 mm) (0.210 mm)
Idler Gear Shaft and Bushing

Reference
Page
1.8091 - 1.9675 in 1.8071 in
Shaft Outside Diameter See
(45.950 - 49.975 mm) (45.900 mm)
Inspection of
1.8110 - 1.8120 in 1.8140 in
Bushing Inside Diameter Idler Gear
(46.000 - 46.025 mm) (46.075 mm)
and Shaft on
0.0010 - 0.0030 in 0.0069 in page 6-47
Clearance
(0.025 - 0.075 mm) (0.175 mm)

ENGINE
Backlash of Each Gear
Reference
Page
Crankshaft Gear, Camshaft Gear, Idler Gear, Fuel Injection 0.0031 - 0.0055 in 0.0063 in
-
Pump Gear (0.08 - 0.14 mm) (0.16 mm)
0.0035 - 0.0059 in 0.0067 in
Lubricating Oil Pump Gear -
(0.09 - 0.15 mm) (0.17 mm)
Cylinder Block
Reference
Page
3.6220 - 3.6232 in 3.6272 in
4TNE92
(92.000 - 92.030 mm) (92.130 mm)
3.7008 - 3.7020 in 3.7059 in See
Cylinder Inside Diameter 4TNE94 Inspection of
(94.000 - 94.030 mm) (94.130 mm)
Cylinder
3.8583 - 3.8594 in 3.8634 in
4TNE98 Block on
(98.000 - 98.030 mm) (98.130 mm)
page 6-40
Roundness 0.0004 in (0.01 mm) 0.0012 in
Cylinder Bore
Inclination or less (0.03 mm)
Crankshaft
Reference
Page
0.0008 in
Bending (1/2 the dial gauge reading) -
(0.02 mm)
2.2816 - 2.2820 in 2.2796 in
Pin Outside Diameter
(57.952 - 57.962 mm) (57.902 mm)
Bearing Halves Inside 2.2835 - 2.2845 in
-
Diameter (58.000 - 58.026 mm)
Connecting Rod Journals
Bearing Halves 0.0587 - 0.0591 in
-
Thickness (1.492 - 1.500 mm) See
Oil Clearance
(0.038 - 0.074 mm) (0.150 mm) Crankshaft
Journal Outside 2.5572 - 2.5576 in 2.5552 in on page 6-45
Diameter (64.952 - 64.962 mm) (64.902 mm)
Bearing Halves Inside 2.5591 - 2.5598 in
-
Diameter (65.000 - 65.020 mm)
Crank Journal Selective Pairing
Bearing Halves 0.0785 - 0.0791 in
-
Thickness (1.995 - 2.010 mm)
0.0015 - 0.0027 in 0.0059 in
Oil Clearance
(0.038 - 0.068 mm) (0.150 mm)

ENGINE
Thrust Bearing
Reference
Page
See Removal
of
0.0043 - 0.0083 in 0.0110 in
Crankshaft Side Gap Crankshaft
(0.11 - 0.21 mm) (0.28 mm)
on page
6-38
Piston
Reference
Page
3.6199 - 3.6211 in 3.6181 in
4TNE92
(91.945 - 91.975 mm) (91.900 mm)
Piston Outside Diameter
3.6986 - 3.6990 in 3.6969 in See
(Measure in the Direction Vertical to 4TNE94
(93.945 - 93.955 mm) (93.900 mm) Inspection of
the Piston Pin.)
3.8559 - 3.8563 in 3.8543 in Pistons on
4TNE98 page 6-44
(97.940 - 97.950 mm) (97.900 mm)
Piston Diameter Measure Position 0.8661 in
-
(Upward From the Bottom End of the Piston.) (22.000 mm)
1.1811 - 1.1815 in 1.1826 in
Hole Inside Diameter
(30.000 - 30.009 mm) (30.039 mm) See
Piston Pin Pin Outside Diameter
(29.989 - 30.000 mm) (29.959 mm) Piston Pin on
0.0000 - 0.0008 in 0.0032 in page 6-44
Clearance
(0.000 - 0.020 mm) (0.080 mm)

ENGINE
Piston Ring
Reference
Page
0.0803 - 0.0811 in
Ring Groove Width -
(2.040 - 2.060 mm)
0.0764 - 0.0772 in 0.0756 in
Ring Width
(1.940 - 1.960 mm) (1.920 mm)
Top Ring
0.0032 - 0.0047 in
Side Clearance -
(0.080 - 0.120 mm)
0.0098 - 0.0177 in 0.0213 in
End Clearance
(0.250 - 0.450 mm) (0.540 mm)
0.0819 - 0.0825 in 0.0864 in
Ring Groove Width
(2.080 - 2.095 mm) (2.195 mm)
0.0776 - 0.0783 in 0.0768 in See
Ring Width
(1.970 - 1.990 mm) (1.950 mm) Inspection of
Second Ring
0.0035 - 0.0049 in 0.0096 in Pistons on
Side Clearance page 6-44
(0.090 - 0.125 mm) (0.245 mm)
0.0177 - 0.0256 in 0.0287 in
End Clearance
(0.450 - 0.650 mm) (0.730 mm)
0.1187 - 0.1193 in 0.1232 in
Ring Groove Width
(3.015 - 3.030 mm) (3.130 mm)
0.1169 - 0.1177 in 0.1161 in
Ring Width
(2.970 - 2.990 mm) (2.950 mm)
Oil Ring
0.0010 - 0.0024 in 0.0071 in
Side Clearance
(0.025 - 0.060 mm) (0.180 mm)
0.0100 - 0.0177 in 0.0217 in
End Clearance
(0.250 - 0.450 mm) (0.550 mm)
Connecting Rod
Reference
Page
See
Inspection of
0.0051 - 0.0091 in
Thrust Clearance - Connecting
(0.13 - 0.23 mm)
Rod on
page 6-45
Rod Small End
Reference
Page
1.1821 - 1.1826 in 1.1838 in
Bushing Inside Diameter See
(30.025 - 30.038 mm) (30.068 mm)
Inspection of
1.1806 - 1.1811 in 1.1795 in
Pin Outside Diameter Connecting
(29.987 - 30.000 mm) (29.959 mm)
Rod on
0.0010 - 0.0020 in 0.0043 in page 6-45
Clearance
(0.025 - 0.051 mm) (0.109 mm)

ENGINE
Tappet
Reference
Page
0.4724 - 0.4732 in 0.4739 in
Cylinder Block Tappet Hole Inside Diameter
(12.000 - 12.018 mm) (12.038 mm) See
Tappet Stem Outside Diameter
(11.975 - 11.990 mm) (11.955 mm) Tappets on
0.0004 - 0.0017 in 0.0033 in page 6-45
Oil Clearance
(0.010 - 0.043 mm) (0.083 mm)

ENGINE
ENGINE SPECIAL TORQUE CHART

Lubricating Oil
Thread Diameter Application
Component Tightening Torque Reference Page
and Pitch (Thread Portion and
Seat Surface)
76.0 - 83.3 ft lbs See Assembly of
Cylinder Head Bolts M11 x 1.25 mm (103.1 - 112.9 N·m, Applied Cylinder Head on
10.5 - 11.5kgf·m) page 6-30
39.8 - 43.4 ft lbs
See Installation of
Connecting Rod Bolts M10 x 1.0 mm (53.9 - 58.8 N·m, Applied
Pistons on page 6-51
5.5 - 6.0 kgf·m)
137.3 - 151.8 ft lbs See Installation of
Flywheel Bolts M14 x 1.5 mm (186.2 - 205.8 N·m, Applied Crankshaft on
19.0 - 21.0 kgf·m) page 6-50
Main Bearing Cap Bolts M11 x 1.25 mm (108.1 - 117.9N·m, Applied Crankshaft on
11.0 - 12.0 kgf·m) page 6-50
Crankshaft Pulley Bolts M14 x 1.5 mm (107.9 - 127.5 N·m, Applied Crankshaft on
11.0 - 13.0 kgf·m) page 6-50

ENGINE
SPECIAL SERVICE TOOLS

No Tool Name Applicable model and tool size Illustration
1 Valve Guide Tool
(For Removing L1 L2 d1 d2
Valve Guides) 0.787 in 2.953 in 0.295 in 0.433 in
(20 mm) (75 mm) (7.5 mm) (11 mm)
Locally Manufactured
0000827
2 Valve Guide Tool

(For Installing L1 L2 d1 d2
Valve Guides) 0.591 in 2.559 in 0.551 in 0.787 in
(15 mm) (65 mm) (14 mm) (20 mm)
0000828
3 Wrist Pin Bushing

Tool L1 L2 d1 d2
(For Removing/ 0.787 in 3.937 in 1.181 in 1.299 in
Installing of Wrist (20 mm) (100 mm) (30 mm) (33 mm)
Pin Bushings)
0000829
4 Valve Spring
Compressor
(For Removing/ Yanmar Part No.
Installing Valve 129100-92630
0000830
Springs)
5 Stem Seal Tool

(for Installing d1 d2 d3 L1 L2 L3
Stem Seals) 0.638 in 0.866 in 0.531 in 0.669 in 2.560 in 0.157 in
(16.2 (22 mm) (13.5 (17.0 (65 mm) (4 mm)
mm) mm) mm)
0000820
6 Filter Wrench
(For Removing /
Installing Engine Available Locally
Oil Filter) 0000821

ENGINE
No Tool Name Applicable model and tool size Illustration
7 Camshaft
Bushing Tool L1 L2 d1 d2
(For Removing 0.709 in 2.756 in 1.969 in 2.087 in
Camshaft (18 mm) (70 mm) (50 mm) (53 mm)
Bushing) -0.3
Allowance: d1 -0.6 d2 -0.3
-0.6
0000822
8 Flex-Hone
(For Preparing Model Part Number Cylinder Bore
Cylinder Walls) 4TNE92
129400-92430 83 - 95 mm
4TNE94
4TNE98 129400-92440 89 - 101 mm
0000823
9 Piston Ring
Compressor Yanmar Part No. 95550-002476
(For Installing The Piston Insertion Tool is Applicable for
Pistons) 2.362 - 4.921 in (60 - 125 mm) Diameter Pistons
0000824
10 Piston Ring Tool

(For Removing/
Installing of Available Locally
Piston Rings)
0000825
11 Crankshaft Pulley
Tool
(For Installing Locally Manufactured
Crankshaft (for 4TNV94L)
Pulley)
0000826

ENGINE
MEASURING INSTRUMENTS
No. Instrument Name Application Illustration
1 Dial Gauge Measurements of shaft bending, and strain and
gap of surfaces
0000831
2 Test Indicator Measurements of narrow or deep portions that

cannot be measured by dial gauge
0000832
3 Magnetic Stand For holding the dial gauge when measuring.
0000833
4 Micrometer For measuring the outside diameters of

crankshaft, pistons, piston pins, etc.
0000834
5 Cylinder Gauge For measuring the inside diameters of cylinder

liners, rod metal, etc.
0000835
6 Calipers For measuring outside diameters, depth,

thickness and width
0000836
7 Depth Micrometer For measuring of valve sink
0000837
8 Square For measuring valve spring inclination and

straightness of parts
0000838

ENGINE
9 V-Block For measuring shaft bend
0000839
10 Torque Wrench For tightening nuts and bolts to the specified

torque
0000840
11 Feeler Gauge For measuring gaps between ring and ring

groove, and shaft joints during assembly
0000841
12 Battery Coolant Tester For checking concentration of antifreeze and the

battery electrolyte charge status
0000843
13 Digital Thermometer For measuring temperatures abcdefghijklmn

abcd efghijk
abcdefghijklmn
abcdefghijklmn
abcdefghijklmnabcdefghijklmnabcdefghijklmn
abcdefghijklmnabcdefghijklmn
0000845
14 Tachometer Contact Type For measuring revolution by contacting the

revolving shaft
0000846
Photoelectric Type For measuring revolution by sensing the 1

reflecting mark on the outer periphery of the
revolving shaft
0000847
2
Fuel High Pressure This measures the revolution regardless of the
Pipe Clamp Type center or periphery of the revolving object

ENGINE
15 Circuit Tester For measuring resistance, voltage and continuity
of electrical circuits
0000848
16 Compression Gauge Kit For measuring compression pressure

Gauge Set Part No. TOL-97190080
0000849
New Compression Test Adaptor Adapter for direct injection 2-valve cylinder head
Adapter Part No. 119802-92950
130
0000850

ENGINE
Before You Begin Servicing
A CAUTION
A WARNING
SEVER HAZARD! FLYING OBJECT HAZARD!

• Stop the engine before you begin to • ALWAYS wear eye protection when
service it. servicing engine and when using
injure your eyes.
servicing it. This could result in a • Failure to comply may result in minor
serious injury. or moderate injury.
0000003en
back long hair, and keep your hands, CAUTION
other body parts and clothing away • Only use the engine oil specified.
from moving / rotating parts. Other engine oils may affect warranty
• Failure to comply could result in death coverage, cause internal engine
or serious injury. components to seize, or shorten
0000010en engine life.
A WARNING contaminating engine oil. Carefully
the cap.
EXPOSURE HAZARD! • NEVER overfill. Overfilling may result
• Always read and follow safety related in white exhaust smoke, engine
precautions found on containers of overspeed or internal damage.
hazardous substances like parts 0000005en

sealant removers.
or serious injury.
0000014en

ENGINE
3. Drain the engine coolant. See Drain, Flush, and
CAUTION Re-fill the Coolant System with New Coolant on
• Only use the engine coolant specified. page 5-35. Disconnect the radiator hoses from
Other engine coolants may affect the engine.
warranty coverage, cause an internal 4. Drain the engine oil. See Replace Engine Oil
build up of rust and scale and / or and Engine Oil Filter on page 5-26.
5. Disconnect the exhaust system from the
• Prevent dirt and debris from exhaust manifold.
6. Remove the engine from the vehicle. Fix the
engine on a horizontal base.
remove the cap.
A CAUTION
Be sure to fix the engine securely to
prevent injury or damage to parts due to
falling during the work.
0000006en
0000009en
7. Clean the engine by washing with solvent, air or

REMOVAL OF ENGINE steam cleaning. Carefully operate so as to
prevent any foreign matter from entering the
1. Disconnect the battery cables at the battery. engine.
A WARNING
SHOCK HAZARD!
electrical system.
or serious injury.
0000009en
2. Disconnect the throttle cable and vehicle

electrical harness from the engine

ENGINE
Cylinder Head Components
(1)
(28) (2)
(27) (29)
(30)
(26) (3)
(25)
(4)
(23)
(24)
(5)
(6)
(22)
(7)
(21)
(20)
(9)
(8) (10)
(19)
(11)
(12)
(13)
(14)
(18)
(16)
(15)
(17)
0001685
Figure 6-1

ENGINE
1. Valve Cover Nut Disassembly of Cylinder Head

2. Valve Cover Nut O-ring Prepare a clean, flat working surface on a
3. Valve Cover workbench large enough to accommodate the
4. Valve Cover Gasket cylinder head assembly. Discard all gaskets,
5. Rocker Arm Shaft O-rings and seals.
6. Rocker Arm Shaft Retaining Screw
7. Cylinder Head Bolt
8. Glow Plug Harness CAUTION
9. Valve Cap Identify all parts and their location using
10. Valve Keepers an appropriate method. It is important
11. Spring Retainer that all parts are returned to the same
12. Valve Spring position during the assembly process.
13. Valve Stem Seal 0000080en
14. Valve Guide
15. Intake Valve 1. Remove the intake manifold bolts
16. Exhaust Valve (Figure 6-2, (1)). Remove the intake manifold
17. Cylinder Head Gasket (Figure 6-2, (3)). Discard the intake manifold
18. Cylinder Head gasket (Figure 6-2, (3)).
19. Glow Plug
20. Glow Plug Cover (5)
21. Push Rod
22. Support Bracket Bolt (4)
23. Rocker Arm Shaft Spring
(5)
24. Support Bracket Stud
25. Support Bracket
26. Rocker Arm (6)
27. Rocker Arm Shaft Retaining Ring (7)
28. Valve Adjusting Screw Lock Nut
29. Valve Adjusting Screw
30. Support Bracket Nut
(2) (3)
0001682
(1)
Figure 6-2
2. Remove the exhaust manifold bolts
(Figure 6-2, (4)) and nuts (Figure 6-2, (5)).
Remove the exhaust manifold (Figure 6-2, (6)).
Discard the exhaust manifold
gasket.(Figure 6-2, (7)).
3. Remove the water pump from the engine. See
Disassembly of Engine Coolant Pump on
page 8-12.
4. Remove the fuel injectors from the cylinder
head. See Removal of the Fuel Injectors on
page 7-35.

ENGINE
Removal of Glow Plugs
1. Remove the glow plug cover (Figure 6-3, (2))
from each of the glow plugs (Figure 6-3, (1)).
(1)
2. Disconnect the glow plug harness
(Figure 6-3, (3)) from the glow plugs.
(2)
3. Remove the glow plugs from the cylinder head
(Figure 6-3, (4)).
F
(3)
(2) (3)
(4)
(1) 0001681
Figure 6-4
3. Remove the valve cover (Figure 6-4, (3)).
(4) Discard the valve cover gasket
(Figure 6-4, (4)).
Figure 6-5
Removal of Rocker Arm Assembly

1. Remove the bolt (Figure 6-6, (1)) and locking
nuts (Figure 6-6, (2)) that retain the rocker arm
0001683
support brackets to the cylinder head.
2. Lift the rocker arm assembly from the cylinder
Figure 6-3
head.
Removal of Valve Cover 3. Lift the push rods from the cylinder head.
1. Remove the valve cover nuts (Figure 6-4, (1)). 4. Number the push rods so that they are
2. Check the condition of the O-ring reinstalled with the same valve tappet and
(Figure 6-4, (2)) on each valve cover nut. rocker arm.
Replace the O-ring if necessary.

ENGINE
(3)
(2) (8)
(7)
(2)
(1) (2)
(1) (2)
(4)
(5) (3)
(6)
0001686
Figure 6-7
0001680
4. If necessary, remove the valve adjusting screw
(Figure 6-7, (7)) and lock nut (Figure 6-7, (8))
Figure 6-6 from the rocker arms.
Disassembly of Rocker Arm Assembly Removal of Cylinder Head
1. Remove the rocker arm shaft alignment screw 1. Loosen the cylinder head bolts following the
(Figure 6-7, (1)) from the support bracket that sequence shown in (Figure 6-8).
secures the rocker arm shaft (Figure 6-7, (2)).
2. Remove the retaining rings (Figure 6-7, (3)) (2)
from the ends of the rocker arm shaft
(Figure 6-7, (2)).
(1)
3. Slide the rocker arm shaft (Figure 6-7, (2)) out
of the rocker arm support brackets
0001687A
(Figure 6-7, (4)), springs (Figure 6-7, (5)), and
rocker arms (Figure 6-7, (6)). 1. Fan Side
Note: The rocker arm shaft fits tightly in the 2. Camshaft Side
rocker arm support brackets. Clamp the Figure 6-8
support bracket in a padded vise and
twist the rocker arm shaft to remove. 2. Remove the cylinder head bolts
Reverse this process when you reinstall (Figure 6-9, (1)).
the rocker arm shaft into the support 3. Lift the cylinder head away from the cylinder
brackets. block. Discard the cylinder head gasket
Note: Mark the rocker arms so they can be (Figure 6-9, (2)). Position the cylinder head on
reinstalled with the original matching the work bench to prevent damage to the
valve and pushrod. combustion surface.

ENGINE
4. Slowly release the tension on the valve spring.
(1) 5. Remove the spring retainer (FIgure 6-11, (3)),
valve spring (FIgure 6-11, (4)) and valve stem
seal (FIgure 6-11, (5)).
(1)
(2)
(3)
(4)
(5)
(2)
(6)
0001684
0001690 FIgure 6-11

Figure 6-9 6. Repeat this procedure until all the intake and
exhaust valve springs and valve stem seals are
Removal of Intake / Exhaust Valves removed.
1. Place the cylinder head on the work bench with Note: If you are going to reinstall the valves in
the combustion side down. the cylinder head, mark them so they
2. Using the valve spring compressor tool, can be installed in their original location.
compress one of the valve springs 7. Turn the cylinder head so the exhaust port side
(Figure 6-10). faces down. Remove the intake and exhaust
valves (FIgure 6-11, (6)) from the cylinder
head.
Removal of Valve Guides

1. Using a drift pin and hammer, drive the valve
guides (Figure 6-12, (1)) out of the cylinder
head.
0000191
Figure 6-10
3. Remove the valve keepers (FIgure 6-11, (2))
and valve cap (Figure 6-10, (1)) from the end of
the valve.

ENGINE
A CAUTION
• When replacing a fuse, be sure to turn
(1) off the power by turning the starter
switch key to the OFF position.
• Using the wrong fuse or shorting out a
fuse holder could damage the gauges,
the electrical equipment and the wiring
due to overheating.
• If a new fuse blows out immediately
after replacement, there may be a
001689 problem with the electrical system. As
your dealer for assistance.
Figure 6-12
• If a fuse blows out frequently, contact
Cleaning of Cylinder Head your authorized Yanmar deaer or
distributor for help.
Components
0000018en
Thoroughly clean all components using a
non-metallic brush and an appropriate solvent.
Each part must be free of carbon, metal filings and Inspection of Push Rods
other debris.
Push Rod Straightness
Inspection of Cylinder Head Determine if the straightness of the push rods are
Components within the specified limit.
Visually inspect the parts. Replace any parts that 1. Place the push rods on a flat inspection block or
are obviously discolored, heavily pitted or otherwise layout bed.
damaged. Discard any parts that do not meet its 2. Roll the push rods until a gap can be observed
specified limit. between a portion of the push rod and the
surface of the block or layout bed.
A CAUTION 3. Use a feeler gauge to measure the gap
• Do not push the wiper switch when the (Figure 6-13). See Push Rod on page 6-6 for
tank is empty. It could cause pump the service limit.
failure.
• Wiping the dry windshield could
damage the glass. Use the wiper only
when the windshield is wet.
• The wiper blade may freeze in cold
weather. Do not attempt to move it;
otherwise the wiper motor will be
damaged.
0000017en
0000204
Figure 6-13

ENGINE
Inspection of Rocker Arm Assembly Use a test indicator and micrometer to measure the
inside diameter at each end of the valve guide. See
Arm Shaft Hole Diameter Intake / Exhaust Valve and Guide on page 6-5 for
Use a test indicator and micrometer to determine if the service limit.
the inside diameter of all the rocker arm support
brackets and the rocker arms (Figure 6-14) are Inspection of Cylinder Head
within the specified limits. See Rocker Arm and
Cylinder Head Distortion
Shaft on page 6-6 for the service limit.
Place the cylinder head flat and inverted
(combustion side up) on the bench. Use a straight
edge and feeler gauge to measure the amount of
cylinder head distortion (Figure 6-16). See
Cylinder Head on page 6-5 for the service limit.
.
Figure 6-14
Shaft Outside Diameter

Use a micrometer to measure rocker arm shaft
0000192
diameter in at least four places (Figure 6-15). See
Rocker Arm and Shaft on page 6-6 for the service Figure 6-16
limit.
Inspection of Intake and Exhaust Valves
.
Visually inspect the intake and exhaust valves.

Replace any valves that are obviously discolored,
heavily pitted or otherwise damaged.
Valve Stem Diameter

Use a micrometer to measure the valve stem
diameter. Measure the valve stem near the
combustion end and near the opposite end
(Figure 6-17). See Intake / Exhaust Valve and
Guide on page 6-5 for the service limit.
0000203
Figure 6-15
Inspection of Valve Guides (1)
Guide Inside Diameter

Visually inspect the valve guides for distortions, 0000197
scoring or other damage.

Figure 6-17

ENGINE
Valve Stem Straightness
Place the valve stem on a flat inspection block or
layout bed. Roll the valve until a gap can be
observed between a portion of the valve stem and
the surface of the block or bed. Use a feeler gauge
to measure the gap (Figure 6-18). See Intake /
Exhaust Valve and Guide on page 6-5 for the
service limit.
0001755
Figure 6-20
Valve Seat
Always check the clearance between the valve and

valve guide before correcting the valve seat
(Figure 6-21, (1)). If the clearance exceeds the
limit, replace the valve or valve guide to bring the
0000199 clearance within the limit.
Figure 6-18 Roughness, or burrs will cause poor seating of a
valve. Visually inspect the seating of each valve
Valve Sink and determine if lapping or grinding is needed.
Insert the valves into their proper places and press Grinding is needed if the cylinder head’s seat width
them down until they are fully seated. Use a depth exceeds standard limits. See Cylinder Head on
micrometer (Figure 6-19) to measure the page 6-5 for the service limit.
difference between the cylinder head surface and
the combustion surface of each exhaust and intake
valve (Figure 6-20). See Cylinder Head on
page 6-5 for the service limit.
(1)
0000193 0001691A
Figure 6-19
Figure 6-21
Lap the valve seat and cylinder head with a mixture
of valve compound and engine oil.

ENGINE
If the valve requires grinding, lap the valve after
grinding.
Be sure to thoroughly wash the parts to remove all
grinding powder or compound.
2
3
1
4
Inspection of Valve Springs
5
9
6
8
7
Inspect the valve springs. If damage or corrosion is
seen, or if measurements exceed the specified
limits, replace the springs.
Fractures
Check for fractures on the inside and outside 0000200
portions of the springs. If the valve spring is Figure 6-23

fractured, replace the valve spring.
Assembly of Cylinder Head
Corrosion
Check for corrosion of spring material caused by Assembly of Valve Guides
oxidation. 1. The valve guides are installed into the cylinder
Square head with an extremely tight press fit. Before
installing the valve guides, place the valve
Use a flat surface and a square to check each guides in a freezer for at least twenty minutes
spring for squareness (Figure 6-22). See Valve This will cause the valve guides to contract,
Spring on page 6-6 for the service limit. making it easier to install the valve guides into
place.
2. Immediately after removing the valve guides
from the freezer, insert the valve guides
(Figure 6-24, (1)) in their proper positions.
(1)
0000201
Figure 6-22
Free Length
Use a caliper to measure the length of the spring
(Figure 6-23). See Valve Spring on page 6-6 for 001689
the service limit.
Figure 6-24

ENGINE
3. Finish installing the valve guides
(Figure 6-25, (1)) into the cylinder head to the
proper height (Figure 6-25, (3)) using the valve
guide installation tool (Figure 6-25, (2)). See
Stem seal
Intake / Exhaust Valve and Guide on page 6-5.
Clearance
Valve
(2) guide
(3)
Valve guide protection
(1) Stem seal protection 0001758
0001756A
Figure 6-27
Figure 6-25
2. Place the cylinder head assembly on its
Assembly of Intake and Exhaust Valves exhaust port side.
1. Oil the lip of the valve stem seal. Using the 3. Place all the valves (Figure 6-28, (6)) in their
valve stem seal installation tool, insert a new proper place in the cylinder head.
valve stem seal (Figure 6-28, (5)) on each of
the valves. (1)
(2)
Valve stem seal inserting tool
(3)
(4)
(5)
Stem seal
Valve guide
Cylinder head (6)
0001684
Stem seal Insertion 0001757
Figure 6-28
Figure 6-26
4. Place the cylinder head on the workbench with
• Measure the distance from the cylinder head to the combustion side down to install the valve
the valve stem seal. See Intake / Exhaust Valve springs. Install the valve spring
and Guide on page 6-5. (Figure 6-28, (4)) and spring retainer
(Figure 6-28, (5)).

ENGINE
5. Using the valve spring compressor tool,
compress the valve spring. (2)
6. Insert the valve keepers (Figure 6-28, (2)) and

slowly release the tension in the valve spring. (1)
Install the valve cap (Figure 6-28, (1)). Repeat
these steps until all the intake and exhaust 0001688A
valves are installed.
1. Fan Side
Assembly of Cylinder Head 2. Camshaft Side
1. Carefully clean both the combustion surface of Figure 6-30
the cylinder head and the top surface of the
cylinder block. Then place a new cylinder head First Step 11 - 13 ft lbs
gasket (Figure 6-29, (2)) on the cylinder block. (49-58.8 N m)
2. Position the cylinder head on the cylinder head (5 - 6 kgf m)
gasket. Second Step 23 - 25 ft lbs
(103.1 - 112.9 N m)
(10.5 - 11.5 kgf m)
(1)
4. Insert the push rods in their respective
positions.
Assembly of Rocker Arm Assembly

1. Lubricate the rocker arm shaft. Slide the rocker
arm support brackets (Figure 6-30, (4)),
springs (Figure 6-30, (5)) and rocker arms
(Figure 6-30, (6)) onto the shaft.
Note: The rocker arm shaft fits tightly in the
rocker arm support brackets. Clamp the
(2) support bracket in a padded vise and
twist the rocker arm shaft to remove.
Reverse this process when you reinstall
the rocker arm shaft into the support
brackets.
Note: To properly align the rocker arm shaft
with the rocker arm shaft supports, first
install the rocker arm support bracket
(Figure 6-31, (4)) with the hole for the
0001690
shaft alignment screw (Figure 6-31, (1)).
Align the hole in the rocker arm shaft and
Figure 6-29
the hole in the rocker arm support
3. Lightly oil the threads of the cylinder head bolts bracket. Install the alignment screw.
(Figure 6-29, (1)). Torque the bolts in steps to
the specified torque in table following the
sequence in (Figure 6-30).

ENGINE
(3)
(8)
(7)
(1)
(1) (2) (2)
(4) (3)
(5) (3)
(6)
0001686 (4)
Figure 6-31 0001681
2. Position the rocker arm assembly on a flat Figure 6-32

surface. Install the retaining rings
(Figure 6-31, (3)) onto the end of the rocker Assembly of Glow Plugs
arm shaft. 1. Install the glow plugs (Figure 6-33, (1)) into the
3. Install and hand tighten the rocker arm shaft cylinder head (Figure 6-33, (4)). Torque the
retaining bolt and nuts. glow plugs to the specified torque.
4. Install the valve adjusting screws 2. Connect the glow plug harness
(Figure 6-31, (7)) and lock nuts (Figure 6-33, (3)) to the glow plugs.
(Figure 6-31, (8)). 3. Install the glow plug cover (Figure 6-33, (2)) on
5. Place the rocker arm assembly in place onto each glow plug.
the cylinder head. Tighten the rocker arm
support bracket nuts and bolt to the specified
torque. Tighten the rocker arm shaft alignment
screw.
(2) (3)
6. Align the push rods with their respective rocker
arms and adjust the valve lash. (See Measuring
and Adjusting Valve Clearance on page 6-32.) (1)
Assembly of the Valve Cover

1. Lightly grease a new valve cover gasket
(Figure 6-32, (4)). Place the gasket in the (4)
groove of the valve cover (Figure 6-32, (3)).
2. Place the valve cover on the cylinder head.
3. Be sure O-rings (Figure 6-32, (2)) are installed
on the valve cover nuts.Install and tighten the
valve cover nuts (Figure 6-32, (1)).
0001683
Figure 6-33

ENGINE
MEASURING AND ADJUSTING (1)

VALVE CLEARANCE
Make measurement and adjustment while the
engine is cold.
Valve Clearance Measurement

1. Remove the valve cover.
2. Rotate the crankshaft clockwise as seen from
the radiator side, to bring No.1 piston to TDC
while watching the rocker arm motion, timing
scale and the top mark position of the
crankshaft pulley. (Position where both the 0001782A
intake and exhaust valves are closed.)
Figure 6-34
Notes:
4. Rotate the crankshaft 180° then make
• The No. 1 piston position is on the flywheel end adjustment for the No. 3 cylinder. Then adjust
of the engine, opposite side of the radiator, and the No. 4 cylinder and No. 2 cylinders in this
the ignition order shall be 1-3-4-2-1 at 180° order. The cylinder to be adjusted first, does not
intervals. have to be the No. 1 cylinder. Select and adjust
• Since the intake and exhaust valve rocker arms the cylinder where the piston is nearest to the
are operated the same and there is a clearance top dead center after turning, and make
between rocker arm and valve generally at the adjustment for other cylinders in the order of
top dead center, the position can be checked ignition by turning the crankshaft 180° each
by means of the play when the arm head is held time.
with a hand. Also see that the crankshaft pulley
top mark is positioned at zero on the timing
scale. If there is no valve clearance, inspection
in the disassembled state is necessary since
the valve seat may be worn abnormally.
3. Insert a feeler gauge (Figure 6-34, (1))
between rocker arm and valve cap, and record
the measured valve clearance. (Use the data
for estimating the wear.)

ENGINE
Valve Clearance Adjustment (1)
1. Loosen the valve adjusting screw lock nut
(Figure 6-35, (1)) and valve adjusting screw
(Figure 6-35, (2)) on the rocker arm and check
the valve for any inclination of valve cap,
entrance of dirt or wear.
(2)
0001782A
Figure 6-36
Item Standard
0.006 - 0.010 in
Valve Clearance
(0.15 - 0.25 mm)
(1)
0001783A 3. Apply oil to the contact surface between
adjusting screw and push rod.
Figure 6-35
4. Turn the crankshaft 180° then make adjustment
2. Insert a 0.008 in (0.2 mm) feeler gauge for the No. 3 cylinder. Then adjust the No. 4 and
(Figure 6-36, (1)) between rocker arm and No. 2 cylinders in this order. The cylinder to be
valve cap, and adjust the valve clearance so adjusted first does not have to be the No. 1
there is a slight “drag” on the feeler gauge when cylinder. Select and adjust the cylinder where
sliding it between the rocker arm and the valve the piston is the nearest to the TDC after
cap. Tighten the valve adjusting screw lock nut rotating and make adjustment for other
(Figure 6-35, (1)) and recheck the clearance. cylinders in the order of ignition by turning the
Note: There is a tendency for the clearance to crankshaft 180° each time.
decrease slightly when the lock nut is
tightened. It is suggested that you make
the clearance adjustment slightly on the
“loose” side before tightening the lock
nut.

ENGINE
DRIVE TRAIN AND CAMSHAFT COMPONENTS

(1)
(3)
(2)
(37)
(36)
(4)
(34)
(33) (5)
(32) (30) (6)
(35) (7)
(31) (8)
(9)
(27) (12)
(29) (13) (11)
(26) (10)
(28) (14)
(25)
(24) (18) (17)

(23) (16)
(15)
(22)
(19)
(20)
(21)
0001736A
Figure 6-37

ENGINE
1. Cylinder Block Disassembly of Drive Train and

2. Camshaft Bushing Camshaft Components
3. Gear Case For ease of disassembly, inspection and
4. Tappets reassembly, it is recommended that the engine be
5. Camshaft mounted in a suitable engine repair stand.
6. Camshaft Gear Key
7. Camshaft End Plate Prepare a clean, flat working surface on a
8. Camshaft Gear workbench large enough to accommodate the
9. Gear Case Cover engine components. Discard all used gaskets,
10. Idler Gear Shaft O-rings and seals.
11. Idler Gear Bushing
12. Idler Gear Remove the cylinder head. See Disassembly of
13. Oil Sump Pump O-ring Cylinder Head on page 6-21.
14. Oil Sump Pump If necessary, remove the fuel injection pump. See
15. Crankshaft Pulley Removal of Fuel Injection Pump on page 7-28.
16. Crankshaft Gear
17. Crankshaft Gear Key
18. Parallel Pin CAUTION
19. Crankshaft Bearing Halves Identify all parts and their location using
20. Crankshaft Main Bearing Cap an appropriate method. It is important
21. Oil Pan that all parts are returned to the same
22. Thrust Bushings position during the assembly process.
23. Crankshaft 0000080en
24. Flywheel
25. Connecting Rod Cap
26. Connecting Rod Bearing Halves
27. Connecting Rod
28. Wrist Pin Bushing
29. Circlip
30. Wrist Pin
31. Piston
32. Oil Ring
33. Second Compressor Ring
34. Top Compressor Ring
35. O-Rings
36. Crankshaft Rear Seal
37. Crankshaft Rear Seal Housing

ENGINE
Removal of Oil Pan Removal of Oil Sump Pump
1. Invert the engine (oil pan up) on the engine 1. Remove the two oil sump tube bolts.
stand.
2. Remove the oil pan bolts from the engine.
(2)
(1)
(1)
0001696A
Figure 6-39
2. Remove the oil sump tube (Figure 6-39, (1))
0001695A and O-ring (Figure 6-39, (2)).
Figure 6-38 Removal of Timing Gears
3. Remove the oil pan (Figure 6-38, (1)). Do not remove the camshaft gear from the
Thoroughly clean all old sealant from the oil camshaft.
pan.
1. Remove the bolt and washer retaining the
crankshaft pulley.
2. Using a gear puller, remove the crankshaft
pulley.
3. Remove the gear case cover (Figure 6-40, (1)).
• Thoroughly clean all sealant from the cover
and the gear case.
• If necessary, remove the seal
(Figure 6-40, (2)) from the cover.

ENGINE
(2)
(1) (3)
(1)
(2)
0001728A
0001735A
Figure 6-42
Figure 6-40 Removal of Pistons
4. Remove the bolts from the timing gears.
CAUTION
• Remove the crankshaft gear
(Figure 6-41, (1)). If using a gear puller, be Keep the piston pin parts, piston
careful not to damage the treads in the end of assemblies and connecting rod
the crankshaft. Remove the parallel pin assemblies together to be returned to
(Figure 6-41, (2)) and the key the same position during the
(Figure 6-41, (3)) from the crankshaft. reassembly process. Label the parts
using an appropriate method.
0000087en
(2)
(3) Note: It is necessary to rotate the crankshaft to
(1)
access some of the connecting rod
assemblies at the bottom dead center
position.
0001731A 1. Using a feeler gauge, measure the connecting
Figure 6-41 rod thrust clearance as shown (Figure 6-43).
See Connecting Rod on page 6-10 for the
• Remove the bolts from the idler gear shaft. standard limit. If the measurement is out of
Remove the idler gear shaft (Figure 6-42, (1)), specification, either the crankshaft or the
idler gear (Figure 6-42, (2)) and bushing connecting rod must be replaced.
(Figure 6-42, (3)).

ENGINE
5. Tap the piston through the cylinder and remove
the piston assembly with the large portion of the
connecting rod. Place this assembly on the
bench. Mark the connecting rod caps and the
connecting rods so the caps and connecting
rods stay together.
6. Using a ring pliers, remove the two
compression rings (Figure 6-44, (3)) from the
piston.
7. Using a ring pliers, remove the oil seal ring
(Figure 6-44, (4)) from the piston.
8. Using a snap-ring pliers, remove the circlips
(Figure 6-44, (5)) from the wrist pin.
0000219 9. Dissemble the wrist pin (Figure 6-44, (6)), wrist
Figure 6-43 pin bushing (Figure 6-44, (7)), connecting rod
(Figure 6-44, (8)) and piston (Figure 6-44, (9)).
2. Remove the two bolts from one of the 10. Repeat Steps 1 through 9 until all of the pistons
connecting rod caps (Figure 6-44, (1)). are removed and dissembled.
(3) Removal of Crankshaft
(4) 1. Remove the flywheel bolts from the flywheel
(Figure 6-45, (1)). Lift the flywheel away from
(5) the engine.
(9) (6) 2. Remove the bolts from the rear oil seal
(5) assembly (Figure 6-45, (2)). Remove the
assembly from the engine. Thoroughly clean all
sealant from the oil seal housing.
(8) 3. Remove the rear oil seal (Figure 6-45, (3)) if
(7) necessary.
(2)
(1)
(2)
(3)
0001705A (1)
Figure 6-44
3. Remove the connecting rod cap.
4. Remove the bearing halves (Figure 6-44, (2)).
0001707A
Figure 6-45

ENGINE
4. Before removing the main bearing caps, 5. Remove the main bearings caps
measure the crankshaft side gap. Use either of (Figure 6-48, (1)), the bearing halves
the following two methods. (Figure 6-48, (3)) and the thrust bearings
• Method A - Install a dial gauge on the cylinder (Figure 6-48, (2)). Be sure to note the markings
block. Move the crankshaft back and forth. on the main bearing caps, or mark them
Measure the side gap. See Thrust Bearing on yourself, so they can be reinstalled in the same
page 6-9 for the service limit. order as they were removed.
Note: The “arrows” on the main bearing caps
point to the flywheel end of the engine.
(Side gap measurement 1)

0001716
Figure 6-46 (2)
• Method B - Use a feeler gauge to measure the

clearance (Figure 6-47, (3)) between the
thrust bearing (Figure 6-47, (1)) and
crankshaft (Figure 6-47, (2)). See Thrust
Bearing on page 6-9 for the service limit. (1)
(3)
0001752A
Figure 6-48
(1)
(2) 6. Remove the crankshaft from the engine.
Removal of Camshaft
1. Before removing the camshaft gear and
camshaft, check the camshaft side gap.
(3)
• Using a feeler gauge, measure the camshaft
0001962
side gap. See Camshaft on page 6-7 for the
Figure 6-47 service limit.

ENGINE
5. With the camshaft out of the way, remove the
Thrust
metal tappets. Mark the tappets so they can be
reinstalled in the same location.
Removal of Gear Case

1. Remove the gear case bolts.
2. Remove the gear case (Figure 6-51, (1)) from
the cylinder block. Thoroughly clean all old
sealant from the gear case and cylinder block.
3. If damaged, remove the camshaft bushing
Camshaft side gap Side gap (Figure 6-51, (3)).
0001710
4. Remove the two O-rings (Figure 6-51, (2)) from
Figure 6-49 the cylinder block.
=
2. Using a gear puller, remove camshaft gear.

Remove the key from the camshaft.
3. Remove the two bolts retaining the camshaft
thrust plate (Figure 6-50, (1)). Remove the
camshaft thrust plate. (1)
(3)
(2)
(1)
(2)
0001737A
Figure 6-51
Inspection of Drive Train and

0001706A
Camshaft Components
Figure 6-50
Thoroughly clean all of these components using a
4. With the engine installed in an engine stand, brush and an appropriate solvent. Each part must
rotate the engine so that gravity causes the be free of carbon, metal filings and other debris.
tappets to drop away from the camshaft lobes.
Slowly pull the camshaft (Figure 6-50, (2)) out Inspection of Cylinder Block
of the engine. 1. Ensure that oil holes are clear and
Note: If the engine is not installed on an engine unobstructed. Clear any holes as needed.
stand, position the engine with the 2. Check for discoloration or evidence of cracks. If
mounting flange (flywheel end) facing evidence of a fracture is found, use the color
down. Rotate the camshaft a few turns to check method or the Magnaflux method to
bump the tappets out of the way to determine if the cylinder block is fractured.
prevent the tappets from interfering with
the removal of the camshaft

ENGINE
3. Inspect cylinder roundness and cylindricity for Select the greatest of values X, Y and Z and
evidence of distortions. Collect and record the record it as V. This value represents the
measurements. (See Cylinder Measurement roundness of the cylinder.
Worksheet on page 6-43). Perform the
calculations as follows: • Cylindricity - Cylindricity for cylinder number
one is as calculated as follows:
• Measure the inside diameter of cylinder
number one, near the top of the cylinder (a) and Select the least value of values X, Y and Z
in the (d) direction. Record that measurement record that value as S. Complete the
as data f. calculation as follows:
• Measure the inside diameter of cylinder V–S = W

number one, near the top of the cylinder (a) and
W is the difference between the L and S
in the (e) direction. Record that measurement
measurements. This value represents the
as data g.
cylindricity of the cylinder.
number one, near the center of the cylinder (b) Repeat the Cylindricity and roundness
and in the (d) direction. Record that measurements and calculations for the
measurement as data h. remaining cylinders.
• Measure the inside diameter of cylinder Compare the worksheet findings with the
number one, near the center of the cylinder (b) data in the table.
and in the (e) direction. Record that
Consider honing, re-boring or replacing the
measurement as data i.
cylinder block if the measurements fall outside
• Measure the inside diameter of cylinder specification.
number one, near the bottom of the cylinder (c)
and in the (d) direction. Record that
measurement as data j.
number one, near the bottom of the cylinder (c)
and in the (e) direction. Record that
measurement as data k.
• Roundness - Roundness for cylinder number
one is as calculated as follows:
f–g = X
h–i = Y
j–k = Z
X is the difference between the f and g

measurements at the top of the cylinder.
Y is the difference between the h and i
Z is the difference between the j and k

ENGINE
a 20mm
(12/16 in.)
d
b
e
c
20mm
(12/16 in.) 0000230
Figure 6-52

ENGINE
Cylinder Measurement Worksheet
Cylinder
Measurements Calculated Values
Number
Greatest of
Top Dimension (d) Dimension (e) f-g=X X, Y and Z = V
(a) f =__________ g =__________ X=__________ Roundness
V =_________
Cylinder # Least of
Center Dimension (d) Dimension (e) h-i=Y
1 X, Y and Z = S
(b) h =__________ i =__________ Y=__________
S =_________
V-S=W
Bottom Dimension (d) Dimension (e) j-k=Z
Cylindricity
(c) j =__________ k =__________ Z=__________
V =_________
Greatest of
(a) f =__________ g =__________ X=__________ Roundness
V =_________
Cylinder # Least of
2 X, Y and Z = S
(b) h =__________ i =__________ Y =__________
S =_________
V-S=W
Cylindricity
(c) j =__________ k =__________ Z=__________
V =_________
Greatest of
(a) f =__________ g =__________ X=__________ Roundness
V =_________
Cylinder # Least of
3 X, Y and Z = S
(b) h =__________ i =__________ Y=__________
S =_________
V-S=W
Cylindricity
(c) j =__________ k =__________ Z=__________
V =_________
Greatest of
(a) f =__________ g =__________ X=__________ Roundness
Cylinder # V =_________
4 Least of
(As X, Y and Z = S
(b) h =__________ i =__________ Y=__________
Needed) S =_________
V-S=W
Cylindricity
(c) j =__________ k =__________ Z=__________
V =_________

ENGINE
Inspection of Pistons • Add the top compression ring grove width and
1. Using a micrometer, measure the piston the top compression ring side clearance values
diameter at the skirt as shown (Figure 6-53). together to determine the top ring grove width.
See Piston on page 6-9 for the service limit. See Piston Ring on page 6-10 for the service
limit.
• Replace the piston if the values fall outside
specification.
• Using a feeler gauge, measure the end gap
clearance of the top compression ring.See
Piston Ring on page 6-10 for the service limit.
Approx.
30 mm
Piston ring
0000235
Figure 6-53
Cylinder block
2. Measure the piston ring and piston ring groove
for cylinder number one.
• Using a micrometer, measure the thickness of Head surface
the top compression ring. See Piston Ring on
page 6-10 for the service limit. 0001723
• Place a properly-sized top compression ring in Figure 6-55

the grove as shown (Figure 6-54). Use a feeler
• Measure the rings and ring groves for the
gauge to measure the gap between the ring
second compression ring and oil ring using the
and the piston. See Piston Ring on page 6-10
same method used to measure the top
for the service limit.
compression ring and groove dimensions.
3. Repeat these steps for each of the pistons.
Inspection of Piston Pin

Measure the outside diameter of the piston pin and
the inside diameter of the wrist pin bushing.
Calculate the clearance between the piston pin and
wrist pin bushing. See Piston on page 6-9 for the
Width
service limits.
Thickness
Measuring Side Clearance 0001732
Figure 6-54

ENGINE
Inspection of Tappets
1. Check the tappet contact surfaces with the
camshaft and push rods. Slight surface defects
can be corrected using an oilstone.
0001721
Figure 6-56
Inspection of Connecting Rod

1. Measure the inside diameter if the connecting
rod small end. See Connecting Rod on (1) (2) 0001725
page 6-10 for the service limit.

Figure 6-58
2. Measure the outside diameter of the tappet
stem. See Tappet on page 6-11 for the service
limit.
Tappet stem outside diameter measurement

0001724
0001726

2. Measure the crankpin and connecting rod Inspection of Crankshaft
bushings. Place the connecting rod bushings
(bearing halves) into the connecting rod and 1. Measure the trueness of the crankshaft.
connecting rod cap. Install the end of the • Place the crankshaft on V-blocks positioned at
connecting rod to the rod. Torque the bolts to the end journals.
the specified torque. • Place a dial indicator on a main bearing surface
3. Measure the inside diameter. See and “zero” the gauge.
Crankshaft on page 6-8 for the service limit.

ENGINE
• If the color check method is not available, use
the Magnaflux method. inspect the crankshaft
Bend for cracks. Replace the crankshaft is evidence
of fractures are found.
3. Measure the outside diameter of each crankpin
and journal.
• If the crankpin clearance exceeds the service
Deflection limit, use an undersize bearing. See
Dial gage Crankshaft on page 6-8 for the service limit.
• If the journal clearance exceeds the service
limit, use an undersize bearing. See
Crankshaft on page 6-8 for the service limit.
V-block V-block
Crankshaft bend measurement
0000232
FIgure 6-60
• Rotate the crankshaft and observe the runout.
See Crankshaft on page 6-8 for the service
limit.
• Repeat this measurement operation for each of
the remaining bearing surfaces.
2. Inspect the crankshaft for fractures.
• Using the color check method. Inspect the
crankshaft for cracks. Replace the crankshaft
is evidence of fractures are found.
Crankshaft
journal
Crankpin
Measuring position of the crankpin

and crank journal 0001733
Figure 6-62
Inspection of Camshaft
1. Measure the trueness of the camshaft.
0000231
• Place the camshaft on V-blocks positioned at
the end journals.
Figure 6-61 • Place a dial indicator on the gear side bearing
surface and “zero” the gauge. (Figure 6-63)

ENGINE
(3)
(2)
(1)
0001713A

• Rotate the camshaft and observe the runout.
Inspection of Camshaft Bushings
See Camshaft on page 6-7 for the service limit.
If the camshaft bushing are damaged, replace the
2. Measure the intake / exhaust cam height
bushings using the appropriate service tool.
(Figure 6-64, (1)). See Camshaft on page 6-7
for the service limit. Inspection of Idler Gear and Shaft
1. Measure the outside diameter
(Figure 6-66, (1)) of the idler gear shaft
(1) (Figure 6-65, (2)). See Idler Gear Shaft and
Bushing on page 6-7 for the service limit.
2. Measure the inside diameter (Figure 6-65, (3))
of the idler gear (Figure 6-65, (4)). See Idler
Gear Shaft and Bushing on page 6-7 for the
service limit.
0001712A
(4)
Figure 6-64
3. Measure the gear end (Figure 6-65, (1)),
intermediate position (Figure 6-65, (2)) and (1) (3)
flywheel end (Figure 6-65, (3)) bearing surface
diameters. Determine the oil clearance. The oil (2)
clearance is calculated by subtracting the
measured camshaft bearing surface diameter
from the camshaft bushing inside diameter. See 0001714A
Camshaft on page 6-7 for the service limit.

Figure 6-66

ENGINE
Honing and Boring
Pistons must move freely in the cylinders while
maintaining adequate compression and oil sealing.
If the cylinder walls are scuffed, scored, out of
round or have poor cylindricity, boring or boring and
honing might correct cylinder problems. Re-boring
is necessary if the bore dimensions fall outside
specified limits. Honing must follow any re-boring
operations. Slight imperfections can be corrected
by honing alone. 0000247
1. Boring - Significant cylinder damage might be

Figure 6-68
corrected by re-boring.
• Boring out a cylinder block can only be done in • Saturate the cylinder wall with solvent using a
a properly equipped machine shop. 50-50 mixture of diesel fuel and engine oil.
• After re-boring, existing pistons must be
replaced with over-sized pistons. CAUTION
• After re-boring a cylinder block, each cylinder Do not allow the honing tool to operate
must be honed. in one position for any length of time.
Damage to the cylinder wall will occur.
2. Honing - Slight cylinder imperfections might be Keep the tool in constant up-and-down
corrected by honing. motion.
Note: Tilt the honing tool at a 30 to 40 degree 0000090en
angle during the honing operation, to
leave a cross hatch mark on the cylinder • Rotate the honing tool at 300 to 1200 rpm.
wall. (Figure 6-67) • Insert the rotating honing tool in the cylinder
and move it down through the entire length of
the cylinder in a five-second motion.
0000248

• Insert the appropriate honing tool in the chuck • Without stopping the honing tool, pull it up
of an electric drill. (Figure 6-68) through the entire length of the cylinder in a
five-second motion.

ENGINE
• Maintain the up-and-down motion for thirty to 3. Install one circlip (Figure 6-70, (2)) into the
forty seconds. piston.
• When the honing is completed, wash the 4. Position the connecting rod into the piston
cylinder block with hot water and soap. Use under the skirt. The match marks on the
brushes to clean all passages and crevices. connecting rod must be opposite of the piston
Rinse with hot water and blow dry with identification mark (ID) on the top of the piston.
compressed air. Apply engine oil to all steel
surfaces to prevent rusting.
(2)
Assembly of Drive Train and
Camshaft Components (1)
Notes:
• Proceed slowly. Make no forced assemblies
unless a pressing operation is called for. All
parts must be perfectly clean and lightly (3) 0001719A
lubricated when assembled.

• Use new gaskets, seals and O-rings during
assembly.
Assembly of Pistons
1. Select the parts needed to assemble the piston
and connecting rod for the No.1 cylinder.
0001720
2. Lubricate and insert the wrist pin bushing
(Figure 6-70, (1)) into the small end of the Figure 6-71
piston rod.
5. Lubricate and install the piston wrist pin
(Figure 6-70, (3)) through the piston and wrist
pin bushing.
6. Install the second circlip (Figure 6-70, (4)).
(2) 7. Install the piston rings:
(3) • Use piston ring pliers to install the piston rings.
(4) • Install each piston ring on the piston with the
punched manufacturer’s mark
(Figure 6-72, (1)) facing upward.
(1)
0000225
Figure 6-72
0001705B
• Install the top compression ring, second
Figure 6-70 compression ring and oil ring.

ENGINE
2. Apply ThreeBond Liquid Gasket, Yanmar Part
No. 977770-01212 to the mounting area of the
gear case.
3. Be sure the two O-rings (Figure 6-75, (2)) are
positioned in the cylinder block.
4. Install the gear case (Figure 6-75, (1)). Tighten
the gear case bolts to the specified torque.
0001722
(3) (1)
Figure 6-73
• Stagger the piston ring joints at 120° intervals.
Do not position the top piston ring joint inline
with the piston wrist pin. The coil expander joint
must be opposite the oil ring joint.
(2)
0001737A
Figure 6-75
Installation of Crankshaft
1. Place the crankshaft into the engine.
2. Position the bearing halves (Figure 6-76, (1)),
thrust bearing (Figure 6-76, (2)) and bearing
caps (Figure 6-76, (3)) on the crankshaft.
Note: The numbers and arrows on the main
bearing caps are for proper positioning.
The caps are numbered 1, 2, 3 and 4
with the No. 1 cap at the flywheel. The
arrows on the bearing caps point to the
flywheel end of the engine.
0001718
3. Lubricate the bearing cap bolts and tighten the
Figure 6-74 bolts to the specified torque.
• Repeat these steps for the remaining pistons.
Installation of Gear Case

1. If removed, install a new camshaft bushing
(Figure 6-75, (3)).

ENGINE
(2)
(3)
(1)
(2)
0001707A
Figure 6-77
Installation of Pistons
(1) 1. Lubricate No. 1 piston and piston rings.
2. Using the piston insertion tool (piston ring
compressor), compress the piston rings on the
No.1 piston.
(3) 3. Carefully install the piston into No.1 cylinder. Be
0001752A sure the punched mark on the connecting rod is
facing the fuel injector side and the embossed
Figure 6-76
mark on the connecting rod is facing the
4. Install the rear oil seal housing. flywheel.
• If removed, install a new seal
(Figure 6-77, (3)) in the rear oil seal housing.
• Apply ThreeBond Liquid Gasket, Yanmar Part
No. 977770-01212 to the mounting flange.
• Align the seal housing (Figure 6-77, (2)) with
the two dowel pins
• Install and tighten the bolts to the specified
torque. 0001720
5. Align the flywheel (Figure 6-77, (1)) to the

Figure 6-78
crankshaft.Install the flywheel to the crankshaft
bolts. Tighten the bolts to the specified torque. 4. Install the connecting rod bearing halves
(Figure 6-79, (1)) and connecting rod cap
(Figure 6-79, (2)). Tighten the connecting rod
bolts to the specified torque.

ENGINE
Installation of Timing Gears
1. Lubricate the idler gear (Figure 6-81, (2)),
bushing (Figure 6-80, (3)) and idler gear shaft
(Figure 6-80, (1)). Install the idler gear and idler
(1) gear shaft. Be sure the oil hole in the bushing is
facing toward the top of the engine. Tighten the
(2) idler gear bolts to the specified torque.
0001705C
Figure 6-79
5. Install the remaining pistons in their respective (2)
cylinders.
(3)
Installation of Camshaft (1)
1. Lubricate the tappets. Install the tappets in their
respective locations in the cylinder block. As
when the camshaft was removed, the cylinder
0001728A
block must be in a position that allows gravity to
keep the tappets in place and out of the way of Figure 6-81
the camshaft lobes when the camshaft is
reinstalled. 2. Align the timing gears as follows:
2. Lubricate the camshaft (Figure 6-80, (2)). • Install the crankshaft key in the crankshaft.
Slowly insert the camshaft through the front of Align mark “A” on the crankshaft gear with
the engine. mark “A” on the idler gear and install the gear.
3. Position the camshaft thrust plate • Align mark “B” on the fuel injection pump gear
(Figure 6-80, (1)) to the gear case.Tighten the with mark “B” on the idler gear.
thrust plate bolt to the specified torque. • Install the camshaft key in the camshaft. Align
mark “C” on the camshaft gear with mark “C” on
the idler gear and install the gear.
Fuel injection pump

drive gear
(2) Camshaft gear
(1) B B
C C
Idle gear A
A PTO gear
Crankshaft gear
Lubricating oil
pump gear Direction of rotation
0001706A
0001709

3. When all gears are properly aligned, tighten the
retaining bolts to specified torque.

ENGINE
Installation of Gear Case Cover 3. Install the two oil sump tube bolts. Tighten the
1. Apply ThreeBond Liquid Gasket, Yanmar Part bolts to the specified torque.
No. 977770-01212 to the outside diameter of a
new oil seal (Figure 6-84, (2)). Use oil seal
insertion tool to install the seal. Apply lithium
grease to the lip of the seal.
0001727
(2)
Figure 6-83
(1)
No. 977770-01212 to the mounting area of the
gear case cover (Figure 6-84, (1)).
3. Install the gear case cover bolts. Tighten the
0001696A
bolts to the specified torque.
Figure 6-85
Installation of Oil Pan

No. 977770-01212 to the mounting surface of
the oil pan (Figure 6-86, (1)).
2. Install the bolts. Tighten the bolts to the
(1) specified torque.
(2)
0001735A
Figure 6-84
Installation of Oil Sump Pump

1. Position a new O-ring (Figure 6-85, (2)) on the
oil sump tube.
2. Position the oil sump tube (Figure 6-85, (1)) in
the cylinder block.

ENGINE
(1)
0001695A
Figure 6-86

Section 7
FUEL SYSTEM
TNE Service Manual
Table of Contents
Page
Measuring Instruments.................................................................... 7-3
Fuel System Special Torque Chart ................................................. 7-3
Fuel System Components ............................................................... 7-6
Fuel System Diagram...................................................................... 7-7
Structure and Operation of Fuel Injection Pump ............................. 7-9
Overview.................................................................................. 7-10
Plunger Operation ......................................................................... 7-13
Process.................................................................................... 7-14
Reverse Rotation Prevention Mechanism ............................... 7-16
Fuel Injection Volume Adjustment Mechanism........................ 7-16
Delivery Valve Assembly ......................................................... 7-17
Delivery Valve Holder with Damping Valve ............................. 7-17
All -Speed Governor...................................................................... 7-18
At Start of Engine .................................................................... 7-20
During Idling ............................................................................ 7-21
At Full-Load Maximum Speed Control..................................... 7-22
At No-Load Maximum Speed Control...................................... 7-23
Full-Load Position Adjustment Mechanism ............................. 7-24
Structure and Operation of Timer.................................................. 7-25
Standard Type Automatic Timer.............................................. 7-25
Magnetic Valve (Stop Solenoid) .............................................. 7-26
Before You Begin Servicing .......................................................... 7-27
Removal of Fuel Injection Pump ................................................... 7-28
Installation of the Fuel Injection Pump .......................................... 7-31
Checking / Adjustment of Fuel Injection Timing ............................ 7-33

FUEL SYSTEM
Servicing the Fuel Injectors ........................................................... 7-35
Removal of the Fuel Injectors.................................................. 7-35
Inspection and Testing of the Fuel Injectors............................ 7-36
Judgement Criteria on Atomization Condition ......................... 7-38
Installation of Fuel Injectors..................................................... 7-39

FUEL SYSTEM
FUEL SYSTEM SPECIAL TORQUE CHART

Lubricating Oil Application
Component Tightening Torque (Thread Portion and Seat Reference Page
Surface)
29.4 ft·lbs
See Installation of Fuel
Fuel Injector (39.2 N·m, Not Applied
Injectors on page 7-39
4 kgf·m)
43.5 - 51.0 ft·lbs
Fuel Pump Drive See Installation of the Fuel
(59 - 69 N·m, Not Applied
Gear Nut Injection Pump on page 7-31
6.0 - 7.0 kgf·m)
1 Fuel Injector Tester For measuring injection spray pattern of fuel
injection nozzle and injection pressure
0000844

FUEL SYSTEM
theory of operation of the fuel injection pump, the A WARNING
procedures necessary to remove and install the
fuel injection pump and the procedures for
inspecting and testing the fuel injectors.
A WARNING
EXPOSURE HAZARD!
• Always read and follow safety related
precautions found on containers of
SEVER HAZARD! cleaners, primers, sealants, and
• Stop the engine before you begin to sealant removers.
service it. • Failure to comply could result in death
• NEVER leave the key in the key switch or serious injury.
when you are servicing the engine. 0000014en

engine and not realize you are A CAUTION
serious injury.
or serious injury.
0000010en
A WARNING air, pressurized water or steam may
injure your eyes.
SUDDEN MOVEMENT HAZARD!
• Allow the engine to warm-up for at or moderate injury.
least 5 minutes to allow the engine idle
0000003en
speed to return to normal before
engaging the transmission or any PTO
attachments. Engaging the
transmission or PTO at an elevated
engine speed could result in an
unexpected movement of the
equipment.
or serious injury.
0000006en

FUEL SYSTEM
A CAUTION CAUTION
tamper-proof devices from the full-load
fuel adjusting screw or the high-speed
throttle limit screw on the fuel injection
adjustments have been made at the
PINCH HAZARD! factory to meet all applicable emissions
Carefully rotate the alternator toward the regulations and then sealed.
cylinder block while loosening the NEVER attempt to make any
V-belt. Failure to comply may result in adjustments to these sealed adjustment
minor or moderate injury. screws. If adjustments are required, they
0000014en
0000146en

FUEL SYSTEM
FUEL SYSTEM COMPONENTS
Flyweight
Control Lever
Governor Lever
Drive Shaft Full Load Adjusting Screw
Magnetic Valve
Distributor Head
Feed Pump
Roller Holder
Cam Disc
Plunger
Timer
Delivery Valve
Plunger Spring
0001629
Figure 7-1

FUEL SYSTEM
CAUTION
factory to meet all applicable emissions
NEVER attempt to make any
0000146en
FUEL SYSTEM DIAGRAM

Priming Pump
Overflow Pipe
Overflow Valve
Fuel Filter Magnetic Valve
Drive Shaft Nozzle
Regulating Valve
Plunger Barrel
Feed Pump
Plunger
Oil Separator
0001630
Figure 7-2

FUEL SYSTEM
Fuel is fed from the fuel tank into the fuel inlet of the
injection pump by the feed pump built into the
injection pump via the oil separator and fuel filter.
A filter is installed for fuel filtration. A filter with an oil
separator for water separation is also provided at
the bottom.
Pressure is applied to feed fuel into the fuel inlet by
the feed pump in order to feed fuel into the injection
pump chamber.
Although the fuel pressure in the pump chamber is
proportional to the pump revolution, excessive fuel
is returned to the suction system by the regulating
valve when the pressure exceeds the specified
value. The fuel is then sent to the plunger via the
fuel path in the distributor head. The plunger
applies high pressure to the fuel to feed it to the
nozzle and nozzle holder through the injection pipe.
The overflow valve above the injection pump
functions to maintain constant fuel temperature in
the pump chamber and return excessive fuel to the
fuel tank.

FUEL SYSTEM
STRUCTURE AND OPERATION OF FUEL INJECTION PUMP
Governor Spring
Flyweight
Idle Spring
Full Load Adjusting Screw

Control Lever
Control Lever Shaft Tension Lever

Governor Lever Assembly
Regulating Valve Magnet Valve
Plunger
Outlet Port
Drive Shaft
Feed Pump Delivery Valve
Drive Gear Control Sleeve

Plunger Spring
Cross Coupling
Cam Disc
0001631
Figure 7-3

FUEL SYSTEM
Overview Governor
Pump Control Lever Shaft
Governor Spring
Drive Shaft Control Lever
Cross Coupling Retaining Pin
Cam Disc Magnetic Valve
Distributor Head Tension Lever

Flyweight Holder Gear
Inlet Port Flyweight Holder
Roller Governor
Lever Assy.
Control Sleeve
Plunger Barrel Drive Gear Ball Pin
Delivery Valve
Outlet Port 0001632 Flyweight
Governor Sleeve
Figure 7-4 Control Sleeve
The drive shaft directly receives the engine Plunger

revolution via the timing belt (or gear) and transfers 0001633
it to the cam disc via the cross coupling. Since the Figure 7-5
dowel pin of the cam disc is integrated with the
plunger and fixed in the groove in the plunger collar, The governor is located above the inspection pump
the plunger operates at the same speed as the cam chamber and mainly consists of a flyweight holder
disc. and governor lever assembly. The flyweight holder
holds four flyweights and governor sleeves, and is
The cam disc has a face cam and conducts supported by the governor shaft.
reciprocating operations by the specified cam lift on
the roller in the roller holder assembly. The drive gear engages with the flyweight holder
gear to increase the revolutions of the drive shaft
On the outside of the plunger are two plunger and to turn the flyweight holder assembly. The
springs having the settling force to return the governor lever assembly is secured by the pivot bolt
plunger lifted by the cam disc during the lowering of the pump housing and the ball pin at the bottom
process. Thus, the plunger revolves by means of of the assembly is inserted into the control sleeve
the drive shaft and the reciprocates by means of which slides on the outer periphery of the plunger.
the cam disc. When the fuel fed under high The governor spring at the top of the assembly is
pressure by the plunger reaches the outlet port, the connected to the tension lever by the retaining pin.
delivery valve opens to inject it into the engine The end of the governor spring is connected to the
combustion chamber via the nozzle and nozzle control lever via the control lever shaft. The control
holder. lever is linked to the acceleration pedal via the link
to change the set force of the governor spring
according to the inclined angle. The difference
between the governor spring set force and the
flyweight centrifugal force determines the moving
distance of the control sleeve, thereby increasing or
decreasing the fuel injection volume.

FUEL SYSTEM
Timer Feed Pump (Vane Type)
From Fuel Filter

Roller Holder Regulating Valve
To Pump
Chamber
Roller Holder Pin High

Pressure Side Liner
Rotor
Blade
Timer Piston Drive Shaft
Low Pressure Side 0001635
Timer Spring
0001634 Figure 7-7
Figure 7-6 The feed pump functions to feed fuel from the fuel
At the bottom of the injection pump is the built-in tank to the pump chamber.
timer. A timer spring having a set force is installed The feed pump consists of the rotor, blade (vane)
on the low pressure side of the timer piston. The and liner. The rotor is driven by the drive shaft. The
fuel pressure in the pump chamber is directly liner is located eccentrically to the center of the
applied to the other end (high pressure side) of the rotor and four blades (vanes) are located between
timer piston. The position of the timer piston the rotor and liner. When the rotor turns, the blades
changes according to the balance between the fuel are pressed onto the liner inner wall by centrifugal
pressure and the timer spring force to turn the roller force to change the capacity of the chambers
holder via the roller holder pin. When the piston according to the revolutions. When the capacity of a
moves in the direction to compress the timer spring, chamber increases, it draws fuel from the fuel tank.
the roller holder moves in the advance direction
(counter-revolution direction) to early the injection When the capacity decreases, it feeds fuel into the
timing. Thus, the timer controls the fuel injection pump chamber.
timing according to the fuel pressure in the pump
chamber.

FUEL SYSTEM
Regulating Valve Figure 7-9 shows typical relationships between
pump revolutions and pump chamber pressure.
Fuel Inlet The hydraulic timer directly uses the pump
Regulating Valve chamber pressure for controlling the injection
Spring timing.
Piston
0001636
Figure 7-8
The regulating valve regulates the fuel feeding
pressure of the feed pump so that the fuel pressure
in the pump chamber is maintained within the
specified pressure range.
When the injection pump revolutions increase to
increase the fuel feeding pressure of the feed
pump, the fuel compresses the regulating valve
spring to lift the piston. The fuel is then returned to
the suction side as shown by the arrow in the figure.
It is therefore possible to regulate the pump
chamber pressure by changing the set force of the
regulating valve spring.
Pump Chamber Pressure
Regulating Valve
Activation Point
Pump Revolution
0001637
Figure 7-9

FUEL SYSTEM
PLUNGER OPERATION
Magnetic Valve
Inlet Port
Drive Shaft Drive Gear
Face Cam
Control Sleeve Inlet Slit
Plunger Barrel
Plunger
Cutoff Port Outlet Port Oulet Slit

Feed Pump Roller Cam Disc Plunger Spring Delivery Valve
0001638
The drive shaft simultaneously drives the feed

pump, cam disc and plunger. The plunger spring
presses the plunger and cam disc onto the roller.
When the cam disc turns by means of the drive
shaft, the face cam moves on the roller to activate
the plunger’s reciprocating operation. When the
inlet port of the plunger barrel being pressed into
the distributor head and the inlet slit of the plunger
overlap, the plunger draws fuel and applies
pressure to it.
When the outlet port of the plunger barrel and the
outlet slit of the plunger align, the high-pressure
fuel opens the delivery valve to be injected into the
engine combustion chamber via the nozzle. When
the cutoff port reaches the control sleeve, pressure
feeding from the plunger is terminated.

FUEL SYSTEM
Process Injection Process
Suction Process
Magnetic Valve
Oulet Slit
Inlet Port
Plunger
Inlet Slit
Pressurizing Chamber
Oulet Port 0001645
Figure 7-12
Plunger Spring Delivery Valve Spring
Delivery Valve 0001643
Figure 7-10
0001646
Figure 7-13
0001644
The plunger begins rotating at the same time the
lifting process of the cam disc begins. When the
Figure 7-11 inlet port of the plunger barrel is covered by the
When the inlet port of the plunger barrel overlaps plunger, pressure feeding of fuel is initiated. At the
the inlet slit of the plunger during the lowering same time, the highly pressurized fuel presses up
process of the plunger, the fuel in the pump the delivery valve when the outlet slit of the plunger
chamber is drawn into the plunger. meets the outlet port of the plunger barrel. The fuel
is then injected into the engine combustion
chamber via the nozzle and nozzle holder.

FUEL SYSTEM
End of Injection Uniform Pressure Process
Uniform Pressure Slit
Control Sleeve
Cutoff Port
0001647 Outlet Port 0001649
0001648 0001650

When the plunger is further lifted up by the cam When the plunger turns a further 180° after the end
disc until the cutoff port of the plunger just overruns of fuel injection, the uniform pressure slit of the
the control sleeve, the high-pressure fuel in the plunger meets the outlet port of the plunger barrel.
plunger high-pressure chamber returns to the As a result, the pump chamber is connected to the
pump chamber through the cutoff port. As a result, outlet port, thereby making the pressure in the
the fuel pressure in the plunger becomes lower chamber and outlet port equal. After the uniform
than the set force of the delivery valve spring, so, pressure process, the pressure in the outlet port
the delivery valve closes to terminate pressure becomes uniform, ensuring stable fuel injection.
feeding of fuel.
The suction process through the uniform pressure
process are carried out for each cylinder during
every injection cycle.

FUEL SYSTEM
Reverse Rotation Prevention Fuel Injection Volume Adjustment
Mechanism Mechanism
Cylinder A Cylinder B Inlet Port
Control Sleeve
Inlet Slit
(1) Control Port
(2)
Correction Direction Reverse Direction
(1): Period the outlet port hole is open

(2): Period the inlet port is open Decreasing
0001651
I2 Increasing
Injection
I1 Injection Volume
Volume
Figure 7-18 Effective Stroke 0001652
While the plunger is rotating in the correct direction, Figure 7-19

the fuel is sufficiently drawn into the plunger since
the inlet port of the plunger barrel opens during the The fuel injection volume is increased or decreased
plunger lowering process. The inlet port closes by changing the control sleeve position, resulting in
during the lifting process to inject the fuel. change of the effective stroke. The effective stroke
represents the plunger’s stroke from the time the
On the contrary, the inlet port of the plunger barrel inlet port and inlet slit close until the cutoff port
does not close during the plunger lifting process if overruns the control sleeve, which is proportional to
the engine rotates in the reverse direction. So, the the fuel injection volume. When the control sleeve
fuel is not pressurized, resulting in non-injection moves to the left, the effective stroke (I2)
state. decreases. When the control sleeve moves in the
opposite direction, or to the right, the effective
stroke (I1) increases to increase the fuel injection
volume. The control sleeve position is determined
according to the governor control.

FUEL SYSTEM
Delivery Valve Assembly Delivery Valve Holder with Damping
Valve
Deliver
Valve Spring Delivery Valve Holder
Damping
Valve Spring
Delivery Valve
Orifice
Valve Seat
During Pressure Feeding Damping Valve
Delivery
Valve Spring
Piston
Delivery
Valve
Suck Back
During Pressure Feeding End of Pressure Feeding
Stroke
0001654
Figure 7-21
Start of Suck Back End of Suck Back
(End of Pressure Feeding) 0001653 The delivery valve holder with damping valve
functions to prevent cavitation erosion in the pipe at
Figure 7-20 high speed, unstable fuel injection and secondary
The delivery valve assembly consists of the injection.
delivery valve and valve seat. When high-pressure fuel is fed from the plunger, it
When the pressure of the high-pressure fuel being is mainly sent to the nozzle through the outer
fed from the plunger exceeds the force of the periphery of the damping valve since the damping
delivery valve spring, the delivery valve opens to valve also opens at the same time as the delivery
feed the high-pressure fuel to the nozzle and valve upon completion of each injection cycle.
nozzle holder via the injection pipe. After injection, So, the only fuel path left is the small orifice of the
a certain degree of remaining pressure exists in the damping valve. This permits the slow closing of the
injection pipe ready for the next injection. The delivery valve. Thus, rapid pressure decrease in the
delivery valve prevents the fuel remaining in the pipe is prevented and transfer of the reflection wave
injection pile from returning to the plunger. in the pipe suppressed to ensure stable injection.
If the remaining pressure is excessively high, cutoff Note: Cavitation represents the phenomenon
of the fuel may be adversely affected. where bubbles are generated in the pipe
The delivery valve also functions to improve fuel when the pressure in the pipe drops.
cutoff of the nozzle by drawing back the fuel in the Cavitation erosion means erosion of the
pipe by the amount equal to the suck-back stroke of pipe inner wall as a result of cavitation.
the piston.

FUEL SYSTEM
ALL -SPEED GOVERNOR
Control Lever Governor Spring
Idle Spring
Corrector Lever
Flyweight Holder Tension Lever
Flyweight
Flyweight
Holder Gear Start Spring
Governor Shaft Start Lever
Governor Lever Assembly
Feed Pump
Plunger
Drive Shaft Drive Gear Control Sleeve Spring

Cam Disc
Governor Sleeve
0001655
Figure 7-22
Figure 7-22 shows the composition of the all-speed Governor Spring
governor. Idle Spring
Control
Lever Shaft Tension Lever
Revolution of the shaft is transferred to the
flyweight holder acceleration gear via the drive gear
to turn the flyweight holder.
The flyweight holder is supported by the governor M1
shaft. There are four flyweights in the holder which M2

are installed in such a way that they open outwardly
by means of centrifugal force.
Start Lever Ball Pin
The flyweight movement presses the governor
0001656
sleeve and presses the governor lever assembly to
the right. The governor lever assembly mainly Figure 7-23
consists of the corrector leer, tension lever and start
lever. Corrector lever fulcrum M, is fixed by the pivot The start spring presses the start lever into the
bolt of the pump housing. Furthermore, the governor sleeve at engine start. The start lever
corrector lever cannot move since it is pressed both turns counterclockwise around fulcrum M2 to move
by the spring at the bottom and the full load the control sleeve to the start offset position.
adjusting screw at the top. The tension and start
levers move around shaft M2 as the fulcrum fixed
on the corrector lever.

FUEL SYSTEM
The start and tension levers contact each other and
move together during engine operation. Above the
tension lever is the governor spring which is
connected to the control lever. Movement of the
control lever is capable of changing the set force of
the governor spring. On the upper back of the
tension lever is the idle spring.
The governor is controlled at all speeds by means
of the start, governor and idle springs.
At Start
At Maximum Speed Control

Control Sleeve Position
At Full Load
(Injection Volume)
At Partial Load
At Idling
Pump Revolution
0001657
Figure 7-24
Figure 7-24 shows the typical injection volume
control characteristics of the all-speed governor.

FUEL SYSTEM
At Start of Engine
Maximum Speed
Stopper Bolt
Control Lever
Governor Spring
Idling Stopper Bolt Governor Sleeve
Idling Spring
Flyweight
M3 (Press-in Pin)
Point A
Start Spring
Start Lever
M1 (fixed)
Injection Volume
M2 (fulcrum)
Plunger
Control Sleeve
Pump Revolution
0001658
Figure 7-25
It is necessary to increase the injection volume in
order to improve the starting characteristics at
engine start.
When the accelerator pedal is pressed while the
engine is stopped, the tension lever is pulled until it
comes into contact with press-in pin M3 by
governor spring force.
At the same time, the start lever is released from
the tension lever by the start spring force to press
the governor sleeve to the left. THe flyweight then
closes completely and the start lever moves the
control sleeve to the start increasing position (to the
right) with M2 being the fulcrum.
Thus, the engine can be started easily by lightly
pressing down on the accelerator pedal.

FUEL SYSTEM
During Idling
Idling Stopper Bolt Governing Spring Idle Spring
Flyweight
Tension Lever
Corrector Lever
Governor Sleeve
Start Lever
M2 (fulcrum)
Injection Volume
Control Sleeve
Pump Revolution
0001659
Figure 7-26
When the engine starts and the accelerator pedal is
released, the control lever returns to the idle
position and the tension of the governor spring
becomes zero. Therefore, the flyweight opens
outwardly even at low revolutions to move the
governor sleeve to the right.
This makes the start lever turn clockwise with M2
being the fulcrum to move the control sleeve in the
direction to reduce the fuel volume. The governor
sleeve stops at a point where the flyweight
centrifugal and idle spring force are balanced to
ensure stable idling.

FUEL SYSTEM
At Full-Load Maximum Speed Control
Maximum
Speed Stopper Bolt Idle Spring
Governor Sleeve
Flyweight
Full-Load Adjusting Screw
Tension Lever
Point A
Corrector Lever
M3 (Press-in Pin)
Start Lever
M1 (fixed)
M2 (fulcrum)
Injection Volume
Control Sleeve
Pump Revolution
0001660
Figure 7-27
When the accelerator pedal is pressed down all the
way and the control lever comes into contact with
the maximum speed stopper bolt, the tension of the
governor spring becomes maximum.
At this time, the tension lever is fixed at the position
where is contacts pin M3 being pressed into the
pump housing. The idle spring is completely
compressed to connect the start lever and the
tension lever at point A, thereby holding the control
sleeve at the full-load position. At this time, the
flyweight is pressed by the governor sleeve and is
in the completely closed state.

FUEL SYSTEM
At No-Load Maximum Speed Control
CAUTION
0000146en
Maximum
Speed Stopper Bolt
Governor Spring Idle Spring
Flyweight
Full-Load Adjusting Screw
Corrector Lever
Tension Lever
M3 (Press-in Pin)
Governor Spring
Start Lever
Injection Volume
M1 (fixed)
M2 (fulcrum)
Cutoff Port
Control Sleeve Pump Revolution

0001661
Figure 7-28

FUEL SYSTEM
When the engine revolutions increase and the Idle spring
flyweight centrifugal force exceeds the governor
spring set force, the governor sleeve moves to
make the governor lever assembly turn clockwise
with fulcrum M2. As a result, the control sleeve Full load
adjusting screw
moves in the direction of no-injection (to the left) for
Tension lever
controlling speed so as not to exceed the full-load
Corrector lever
maximum speed.
M3
When the accelerator pedal is not pressed down Start lever
fully, the set force of the governor spring changes
M1 (fixed)
accordingly in order to achieve governor control
M 2 (fulcrum)
based on the governor spring set force during
partial load operation.
Control Fuel increase direction
sleeve
Full-Load Position Adjustment
Effective stroke
Mechanism 0001662
Figure 7-29
CAUTION
The full-load position is determined by the amount
the full-load adjusting screw is driven. When the
screw is driven, the corrector lever turns
counterclockwise with M1 being the fulcrum to
move the control sleeve to the fuel increase
direction.
factory to meet all applicable emissions When the screw is loosened, the control sleeve
regulations and then sealed. moves to the fuel decrease direction.
0000146en

FUEL SYSTEM
STRUCTURE AND OPERATION Consequently, the timer is installed under the

injection pump in order to correct the ignition delay
OF TIMER period by shortening the injection timing of the
The ignition period which occurs in the combustion injection pump.
process of a diesel engine tends to increase as the
speed becomes higher.
Direction of drive shaft rotation

Drive Shaft Direction of roller holder rotation
Roller holder
assembly
Roller
Timer piston
Low High
pressure pressure
side side
Timer spring Pin High pressure chamber
(A) When timer is inactive (B) When timer is active
0001663
Figure 7-30
Standard Type Automatic Timer When pump revolutions increase and the pump
chamber pressure exceeds the set force of the
As shown in Figure 7-30, the inside of the timer timer spring, the timer piston moves in the direction
housing is separated into low and high pressure to compress the spring ([B] in Figure 7-30). This
sides, the latter directly receiving the pump turns the roller holder assembly in the reverse
chamber pressure. A timer spring having a set direction of pump revolution via the pin. This
force is installed in the low pressure side. The timer causes the crest of the cam disc to quickly
piston slides horizontally based on the balance approach the roller position of the roller holder, to
between the spring force and changes in the pump advance the injection timing. On the contrary, when
chamber pressure. The movement of the timer pump revolutions decrease and the timer spring
piston turns the roller holder assembly via the pin. force exceeds the pump chamber pressure, the
timer piston moves in the direction to delay the
timing.

FUEL SYSTEM
Magnetic Valve (Stop Solenoid)
Magnetic valve
Spring
Fuel path Armature
Inlet port
When magnetic valve is on When magnetic valve is off

0001664
Figure 7-31
The magnetic valve (stop solenoid) turns on or off
as the ignition switch of the vehicle is operated to
open or close the fuel path connected to the inlet
port of the plunger barrel.
When the ignition switch is turned on, power is
supplied to the magnetic valve to lift the armature,
thus opening the fuel path.
On the contrary, when the ignition switch is turned
off, the armature is powered by the force of the
spring installed in the armature to close the fuel
path. As a result, no fuel is fed to the plunger,
stopping the engine immediately.

FUEL SYSTEM
BEFORE YOU BEGIN

A CAUTION
SERVICING
A WARNING

SEVER HAZARD! • ALWAYS wear eye protection when
• Stop the engine before you begin to compressed air or high-pressure
service it. water. Dust, flying debris, compressed
• NEVER leave the key in the key switch air, pressurized water or steam may
when you are servicing the engine. injure your eyes.
Someone may accidentally start the • Failure to comply may result in minor
engine and not realize you are or moderate injury.
0000003en
serious injury.
or serious injury.
0000010en
A WARNING
EXPOSURE HAZARD!
sealant removers.
or serious injury.
0000014en

FUEL SYSTEM
REMOVAL OF FUEL INJECTION • Then loosen the high pressure fuel line nuts
(Figure 7-32, (3)) on the fuel injection pump.
PUMP • Finish loosening all the high pressure fuel line
1. Remove fuel supply line from the fuel injection nuts and remove the fuel lines as an assembly.
pump. Be careful not to bend any of the fuel lines.
2. Remove fuel injector return line.
3. Remove fuel tank return line. CAUTION
4. Disconnect the electrical connection to the Remove the high-pressure fuel injection
magnetic valve (stop solenoid) lines as an assembly whenever
(Figure 7-32, (1)). possible. Disassembling the
high-pressure fuel injection lines from
the retainers or bending any of the fuel
lines will make it difficult to reinstall the
(2) fuel lines.
0000047en
Note: It is necessary to remove the bolt

(Figure 7-33, (1)) holding the dipstick
tube clamp. Rotate the dipstick tube to
one side to allow you to remove the high
pressure fuel line assembly.
(1)
(3)
0001734A
Figure 7-32
5. Disconnect the throttle linkage.
6. Remove the high pressure fuel lines.
• First loosen the high pressure fuel line nuts
(Figure 7-32, (2)) at the fuel injectors. (1)
CAUTION 0001699A
When loosening or tightening the lines

at the fuel injectors, you must hold the Figure 7-33
fuel injector with a second wrench to 7. Remove the two bolts (Figure 7-34, (1)) from
prevent the injector from turning and the L-shaped brackets that holds the injection
damaging the fuel return line fitting. pump at the bottom / rear.
0000082en

FUEL SYSTEM
(2) (1)
(3)
0001639B
Figure 7-35
(1) (2) 0001700A 10. Remove the seven bolts from the fuel injection
pump cover (Figure 7-36, (1)) on the front gear
Figure 7-34 case. Remove the cover.
• Loosen the bolt (Figure 7-34, (2)) that fastens Note: The cover is secured with an adhesive
the remaining bracket to the cylinder block and sealant. Use a gasket scraper to
pivot down and away from the injection pump. separate the cover from the gear case.
8. Loosen the alternator adjusting bolt and pivot
the alternator toward the engine.
A CAUTION
PINCH HAZARD!
Carefully rotate the alternator toward the
cylinder block while loosening the
V-belt. Failure to comply may result in
minor or moderate injury.
0001697A
0000014en
(1)
Figure 7-36
9. Remove the cooling fan (Figure 7-35, ((1)),
spacer (if equipped) (Figure 7-35, (2)) and 11. To aid in reassembly, mark one tooth on the idle
V-belt (Figure 7-35, (3)). gear and two teeth on the pump drive gear with
a dot of white paint. See (Figure 7-37).

FUEL SYSTEM
CAUTION
Do not rotate the engine with the
injection pump removed.
0000083en
Fuel injection pump

drive gear
Camshaft gear
B B
C C
Idle gear A
A PTO gear
Lubricating oil
Crankshaft gear (3)
(2)
0001709
(1)
Figure 7-37
0001698A
Also make matching marks (Figure 7-38, (1)) on
the rear of the gear case housing and on the fuel Figure 7-39
injection pump mounting flange before loosening
13. Using a two-bolt gear puller, remove the
the injection pump mounting nuts.
injection pump drive gear (Figure 7-39, (3))
from the injection pump shaft.
Note: The injection pump shaft is tapered with
a woodruff key. Once you have applied
some pressure with the puller. A slight
hammer “tap” on the center puller bolt
will help “pop” the gear from the shaft.
14. Remove the three nuts securing the fuel
injection pump to the rear of the gear case.
15. Remove the fuel injection pump.
16. If the fuel injection pump requires servicing, it
must be taken to an authorized ZEXEL fuel
injection shop.
(1)
0000593
0000593A
Figure 7-38
12. While holding the engine from turning with a
wrench on the crankshaft pulley bolt, remove
the pump drive gear retaining nut
(Figure 7-39, (1)) and lock washer
(Figure 7-39, (2)).

FUEL SYSTEM
INSTALLATION OF THE FUEL 3. Install the drive gear retaining nut

(Figure 7-42, (1)) and washer
INJECTION PUMP (Figure 7-42, (2)). While holding the engine
1. Secure the fuel injection pump mounting flange with a wrench on the crankshaft pulley bolt,
to the rear of the gear case housing with three torque the retaining nut to 43.5 - 51 ft lbs (59-69
nuts. Be sure to match the marks N·m, 5 - 5.4 kgf·m).
(Figure 7-40, (1)) on the rear of the gear case
housing and on the fuel injection pump
mounting flange.
(3)
(2)
(1)
(1)
0001698A
0000593
0000593A
Figure 7-42
Figure 7-40
4. Thoroughly clean all old sealant from the fuel
2. Install the injection pump drive gear injection pump cover (Figure 7-43, (1)) and
(Figure 7-42, (3)) on the injection pump shaft gear case housing. Apply ThreeBond, Yanmar
lining up the two marks you made on the pump Part No. 977770-01212, or equivalent sealant
drive gear with the mark you made on the idle to the fuel injection pump cover. Install the fuel
gear. See (Figure 7-37). injection pump cover on the front gear case with
seven bolts. Tighten the bolts to the specified
Fuel injection pump
drive gear torque.
Camshaft gear
B B
C C
Idle gear A
A PTO gear
Crankshaft gear
Lubricating oil
0001709
Figure 7-41

FUEL SYSTEM
0001697A (1) (2) 0001700A

(1)
5. Reinstall the cooling fan (Figure 7-44, (1)), 9. Reinstall the two bolts (Figure 7-45, (1)) to the
spacer (if equipped) (Figure 7-44, (2)) and L-shaped bracket that holds the injection pump
V-belt (Figure 7-44, (3)). at the bottom / rear. Tighten the two bolts and
the bolt that secures the bracket to the cylinder
(2) (1) block to specified torque.
10. Reinstall the high pressure fuel lines.
• Replace the high pressure fuel lines as an
assembly. Be careful not to bend any of the
high pressure fuel lines.
(3)
• Start all the high pressure fuel line nuts by
hand, leaving those nuts on the fuel injection
pump and fuel injectors untightened.
• Tighten the high pressure fuel line nuts
0001639B
Figure 7-44 (Figure 7-46, (1)) on the fuel injectors.
6. Pivot the alternator away from the engine and
adjust the V-belt tension. See Check and Adjust
Cooling Fan V-belt on page 5-22.
7. Tighten the alternator adjusting bolt. See Check
and Adjust Cooling Fan V-belt on page 5-22.
8. Pivot the bracket that fastens the fuel injection
pump to the cylinder back up and toward the
fuel injection pump. Retighten the bolt
(Figure 7-45, (2)) that fastens it to the cylinder
block.

FUEL SYSTEM
(2)
(1) (1)
0001784
Figure 7-47
3. Locate Yanmar timing tool (P/N 119770-02020)
(3) (Figure 7-48, (1)). Install a dial indicator into
the timing tool.
0001734A
Figure 7-46
20
30
11. Reconnect the throttle linkage.
10
40
12. Reconnect the electrical connection to the
50
magnetic valve (stop solenoid)
(Figure 7-46, (1)). (1)
90
60
80
70
13. Reinstall fuel tank return line.
14. Reinstall fuel injector return line.
15. Reinstall fuel supply line to the fuel injection
pump.
16. Prime the fuel system and check for leaks.
0001753A
Figure 7-48
CHECKING / ADJUSTMENT OF 4. Install Yanmar timing tool (Figure 7-49, (1)),
FUEL INJECTION TIMING into the port where the bolt was removed. This
will provide a reading of the injection pump
1. Using a wrench on the front crankshaft pulley
plunger lift.
bolt, rotate the engine clockwise until the timing
mark on the crankshaft pulley is aligned with
the “O” or TDC (Top Dead Center) mark on the
timing grid of the gear case cover.
2. Remove the center bolt (Figure 7-47, (1)) and

sealing washer from the rear of the fuel
injection pump.

FUEL SYSTEM
9. If the injection timing is not correct, loosen the
three fuel Injection pump mounting nuts and the
bolts retaining the bottom / rear L-shaped
injection pump mounting brackets. Rotate the
injection pump to bring the dial indicator
reading into the correct range.
10. Then retighten the pump mounting nuts and the
mounting bracket bolts.
Note: Rotating the injection pump away from
the engine advances the injection timing.
Rotating the injection pump toward the
engine retards the injection timing.
(1)
11. Remove the timing tool and dial indicator.
0
Replace and tighten the center bolt and sealing
90
10 washer into the injection pump port.
80
20
70
30
60
40
50
0001754A
Figure 7-49
5. Rotate the engine about 25° in the
counterclockwise direction. The dial indicator
should move for approximately the first 10° of
engine rotation and then stop. When you reach
approximately the 25° position, rotate the
engine slightly back and forth to make sure the
needle of the dial indicator does not move.
6. Set the dial indicator to “0”.
7. Rotate the engine in the clockwise rotation until
the timing mark on the crankshaft pulley is
aligned with the mark at 4° or 6° ATDC (After
Top Dead Center) on the timing grid on the gear
case cover.
Note: Timing for the 4TNE92-NMH/NMHA
models is 4° ATDC. Timing for the
4TNE98-NMH is 6° ATDC.
8. If the injection timing is correct, the dial
indicator should read 0.038 - 0.041 in (0.97 -
1.03 mm).

FUEL SYSTEM
SERVICING THE FUEL Removal of the Fuel Injectors

INJECTORS 1. Remove the high pressure fuel lines.
CAUTION
NEVER remove or attempt to remove the (2)
(1)
applicable emissions regulations and (3)
0000146en
0001734A
Figure 7-50
• First just loosen the high pressure fuel line nuts
(Figure 7-50, (2)) at the fuel injectors.
CAUTION
at the fuel injectors, you must hold the
fuel injector with a second wrench to
prevent the injector from turning and
damaging the fuel return line fitting.
0000082en
• Then loosen the high pressure fuel line nuts

• Finish loosening all the high pressure fuel line
nuts and remove the fuel lines as an assembly.
Be careful not to bend any of the fuel lines.

FUEL SYSTEM
Inspection and Testing of the Fuel
CAUTION
Injectors
Remove the high-pressure fuel injection
lines as an assembly whenever Visually inspect the fuel injectors and nozzle
possible. Disassembling the protectors for deposits or damage. Clean and repair
high-pressure fuel injection lines from as necessary.
lines will make it difficult to reinstall the Test Procedure Using a Nozzle Tester
fuel lines. 1. Visually inspect the fuel injectors and nozzle
0000047en protectors for deposits or damage. Clean, repair
or replace as necessary.
Note: It is necessary to remove the bolt 2. Test the fuel injector using an injection nozzle
(Figure 7-51, (1)) holding the dipstick tester. Use clean, filtered fuel or F.I.E.
tube clamp. Rotate the dipstick tube to calibration fluid for the test.
one side to allow you to remove the high
pressure fuel line assembly. 3. Using the correct adaptor, connect the fuel
injector to the high-pressure pipe of the nozzle
tester. Aim the fuel injector into a suitable
container to catch the fuel spray.
A WARNING
• Never inject fuel towards you. Since
the fuel in injected at high presure
from the nozzle, it may penetrate the
skin, resulting in injury.
• Never inject fuel towards a fire source.
Atomized fuel is highly flammable and
may cause fire or skin burning.
0000028en
4. Pump the operating lever of the tester slowly,

observing the pressure reading at the point
(1) where the fuel injector begins spraying fuel. The
fuel injectors for these engines should begin
0001699A spraying fuel at 1711 - 1914 PSI (11.8 - 13.2
MPa). The opening pressure may be adjusted
Figure 7-51 by adding or subtracting internal fuel injector
shims.
2. Unscrew the fuel injectors from the cylinder
head. Also remove the two copper washers and
the nozzle protectors that will remain in the
cylinder head.

FUEL SYSTEM
7. Finally. Pump the operating lever slowly to hold
the pressure steady at a point just below the
“pop off” pressure point. Observe the injector to
see that it is sealing properly and is not
“dripping”.
Abnormal
0001740
Figure 7-52
5. Adding or removing a 0.1 mm shim (shims are
available in 0.4 mm increments) changes the
pressure by 174 - 319 PSI (1.2 - 2.2 MPa).
0001741
1 Figure 7-54
8. If the fuel injector fails any of these tests, it
Nozzle holder should be repaired or replaced as necessary.
Pressure adjusting shim
Nozzle spring
Nozzle spring seat
Valve stop spacer
Nozzle valve
Nozzle body
2 Nozzle case
0001739
Figure 7-53
6. Pump the operating lever more rapidly to
repeatedly “pop” the injector and observe the
spray pattern. See Judgement Criteria on
Atomization Condition on page 7-38 for
examples of “good” and “bad” spray patterns.

FUEL SYSTEM
Judgement Criteria on Atomization Condition
A B C D E
Injection Pattern
0001742
0001743 0001744
0001745 0001746
120 120 120 120 120
0 0 0 0 0
0001747 0001748 0001749 0001750 0001751

Pressure Gauge
Reading Pointer fluctuate Same as A. Pointer stays at a Although the Pressure does
around the valve position near the pointer reaches not increase
opening valve opening the valve even when the
pressure. pressure. opening tester lever is
pressure, the operated.
pressure drop is
large.
Roughly uniform. Atomization is Although Bar shape with Drops (bar
excessively one atomized, the excessive after shape).
Atomization
sided. needle does not drops.
Pattern
pulsate (burner
like shape).
(Normal) 1. Normally 1. Caused by 1. Damage to the 1. Sticking of
caused by excessive seat. needle.
carbon carbon 2. Contamination 2. Excessively
contamination contamination of seat by fine damaged or
of the nozzle of the nozzle foreign worn seat.
tip. tip. particles. 3. Contamination
Possible Cause 2. Sometimes 2. Sometimes 3. Excessively of seat by
caused by caused by worn seat. foreign matter.
flaws in or contamination. 4. Damaged or
damage to the broken
needle tip. internal parts
od nozzle
holder.

FUEL SYSTEM
Cleaning of Nozzle • Tighten the high pressure fuel line nuts
1. Clean the exterior of the nozzle, taking care not (Figure 7-55, (1)) on the fuel injectors.
to damage the needle.
2. Pull out the needle and clean carefully so as not
to damage it. Avoid use of hard, metallic tools. (2)
3. Check for dents, damage, rusting and wear. Pay
special attention to the stem and seat of the
needle.
4. When setting the needle on the nozzle body
after thorough cleaning, check that it falls by its
own weight.
(1)
Installation of Fuel Injectors
1. Install a new copper gasket at the bottom of the
injector well.
2. Install the nozzle protector in the injector well.
3. Install the second copper gasket on top of the
nozzle protector. (3)
4. Install the fuel injectors. Torque to 29.4 ft·lb
(39.2 N·m). 0001734A
5. Install the fuel return line fitting using new Figure 7-55
copper gaskets.
8. Prime the fuel system and check for leaks.
6. Tighten the fuel return line retaining nuts to
32.5 ft·lb (44.1 N·m).
CAUTION
at the fuel injectors, you must hold the
fuel injector with a second wrench to
prevent the injector from turning and
damaging the fuel return line fitting.
0000082en
7. Reinstall the high pressure fuel lines and fuel

return line.
• Replace the high pressure fuel lines as an
assembly. Be careful not to bend any of the
high pressure fuel lines.
• Start all the high pressure fuel line nuts by
hand, leaving those nuts on the fuel injection
pump and fuel injectors untightened.

FUEL SYSTEM

Section 8
COOLING SYSTEM
TNE Service Manual
Table of Contents
Page
Measuring Instruments.................................................................... 8-4
Cooling System Diagram................................................................. 8-6
Model 4TNE92-NMHA............................................................... 8-6
Models 4TNE92-NMH and 4TNE98-NMH................................. 8-7
Engine Coolant Pump Components ................................................ 8-8
Model 4TNE92-NMHA............................................................... 8-8
Models 4TNE92-NMH and 4TNE98-NMH................................. 8-9
Before You Begin Servicing .......................................................... 8-10
Engine Coolant System Check...................................................... 8-11
Disassembly of Engine Coolant Pump .......................................... 8-12
Disassembly of the 4TNE92-NMHA Coolant Pump ................ 8-13
Disassembly of the 4TNE92-NMH and 4TNE98-NMH
Coolant Pumps ........................................................................ 8-13
Cleaning and Inspection................................................................ 8-14
Thermostat .............................................................................. 8-14
Radiator Cap ........................................................................... 8-14
Assembly of Engine Coolant Pump............................................... 8-15
Assembly of the 4TNE92-NMHA Coolant Pump ..................... 8-15
Assembly of the 4TNE92-NMH and 4TNE98-NMH
Coolant Pumps ........................................................................ 8-15
Assembly of All Coolant Pump Models.................................... 8-16

COOLING SYSTEM

COOLING SYSTEM
procedures necessary to service the engine A WARNING
coolant pump.
A DANGER
SEVER HAZARD!
• Stop the engine before you begin to
service it.
SCALD HAZARD! when you are servicing the engine.
• NEVER remove the radiator cap if the Someone may accidentally start the
engine is hot. Steam and hot engine engine and not realize you are
coolant will spurt out and seriously servicing it. This could result in a
burn you. Allow the engine to cool serious injury.
down before you attempt to remove • If you must service the engine while it
the radiator cap. is operating, remove all jewelry, tie
• Securely tighten the radiator cap after back long hair, and keep your hands,
you check the radiator. Steam can other body parts and clothing away
spurt out during engine operation if from moving / rotating parts.
the cap is loose. • Failure to comply could result in death
• ALWAYS check the level of engine or serious injury.
coolant by observing the reserve tank. 0000010en

serious injury. A WARNING
0000002en
A WARNING
EXPOSURE HAZARD!
BURN HAZARD! precautions found on containers of
• Wait until the engine cools before you hazardous substances like parts
drain the engine coolant. Hot engine cleaners, primers, sealants, and
coolant may splash and burn you. sealant removers.
• Failure to comply could result in death • Failure to comply could result in death
or serious injury. or serious injury.
0000014en
0000016en

COOLING SYSTEM
A CAUTION CAUTION
FLYING OBJECT HAZARD! contaminating engine coolant.
• ALWAYS wear eye protection when Carefully clean the radiator cap and
servicing engine and when using the surrounding area before you
compressed air or high-pressure remove the cap.
water. Dust, flying debris, compressed • NEVER mix different types of engine
air, pressurized water or steam may coolants. This may adversely affect the
injure your eyes. properties of the engine coolant.
• Failure to comply may result in minor 0000006en
or moderate injury.
0000003en CAUTION
If the engine coolant pump must be
A CAUTION replaced, replace the engine coolant
pump as an assembly only. Do not
attempt to repair the engine coolant
pump or replace individual components.
0000041en
CAUTION
PINCH HAZARD!
Use a new special O-ring between the
engine coolant pump and the joint. Be
sure to use the special O-ring for each
engine model. Although the O-ring
dimensions are the same as a
0000014en
commercially available O-ring, the
material is different.
0000042en

COOLING SYSTEM
1 Cooling System Tester For checking water leakage
0000842

COOLING SYSTEM
COOLING SYSTEM DIAGRAM

Model 4TNE92-NMHA
(1)
(6)
(2)
(3)
(4)
(5)
0001668A
Figure 8-1
1. Cylinder Head 4. Radiator
2. Thermostat 5. Coolant Recovery Tank
3. Engine Coolant Pump 6. Cylinder Block

COOLING SYSTEM
Models 4TNE92-NMH and 4TNE98-NMH
(1)
(6)
(2)
(3) (4)
(5)
0001669A
Figure 8-2
1. Cylinder Head 4. Radiator
2. Thermostat 5. Coolant Recovery Tank
3. Engine Coolant pump 6. Cylinder Block

COOLING SYSTEM
ENGINE COOLANT PUMP COMPONENTS

Model 4TNE92-NMHA
(1)
(4)
(5)
(6)
(3)
(7)
(8)
(2)
(9)
(10)
(11)
(26)
(12)
(13)
(25) (14) (15)
(23)
(24)
(21)
(22)
(5)
(20)
(19)
(18) (17)
(16)
0001627A
Figure 8-3
1. Coolant Pump Gasket 10. Thermostat Gasket 19. Bolt, M6 x 20 Plated
2. Bolt, M6 x 15 11. Plug, M16 20. Coolant Pump Assembly
3. Plug, M12 x 1.5 12. Gasket 21. Gasket
4. Gasket, Round 13. Bolt, M8 x 55 Plated 22. Cover
5. Plug, NPT 3/8 14. Spacer 23. Mechanical Seal
6. Thermostat Cover 15. Engine Coolant Fan 24. Flange
7. Bolt, M8 x 25 Plated 16. Bolt, M8 x 12 Plated 25. O-ring
8. Gasket 17. Coolant Pump V-pulley 26. Drain Plug
9. Thermostat 18. V-belt

COOLING SYSTEM
Models 4TNE92-NMH and 4TNE98-NMH
(5)
(3)
(1) (4)
(2) (6)
(7)
(8)
(9)
(25) (10)
(26)
(11)
(24)
(12)
(23) (14)
(13)
(22)
(4) (21)
(17)
(18) (16)
(20) (19)
(15)
0001628A
Figure 8-4
1. Coolant Pump Gasket 14. Engine Coolant Fan
2. Plug, M12 x 1.5 15. Bolt, M8x12 Plated
3. Gasket, Round 16. Spacer
4. Plug, NPT 3/8 17. Coolant Pump V-pulley
5. Thermostat Cover 18. V-belt
6. Bolt, M8 x 25 Plated 19. 1/4 Steel Ball
7. Gasket 20. Coolant Pump Pipe
8. Thermostat 21. O-ring
9. Thermostat Gasket 22. Gasket
10. Plug, M16 23. Cover
11. Gasket 24. Bolt, M6 x 16
12. Bolt, M8 x 55 Plated 25. Bolt, M6 x 15
13. Water Pump Assembly 26. Drain Plug

COOLING SYSTEM
BEFORE YOU BEGIN SERVICING
A DANGER A WARNING
SEVER HAZARD!
SCALD HAZARD! • Stop the engine before you begin to
• NEVER remove the radiator cap if the service it.
the radiator cap.
• Securely tighten the radiator cap after serious injury.
the cap is loose.
• ALWAYS check the level of engine other body parts and clothing away
coolant by observing the reserve tank. from moving / rotating parts.
• Failure to comply will result in death or • Failure to comply could result in death
serious injury. or serious injury.
0000002en 0000010en
A WARNING
BURN HAZARD!
or serious injury.
0000011en

COOLING SYSTEM
A WARNING A DANGER
EXPOSURE HAZARD! SCALD HAZARD!

• NEVER remove the radiator cap if the
sealant removers.
the radiator cap.
• Securely tighten the radiator cap after
or serious injury.
0000014en
the cap is loose.
A CAUTION • ALWAYS check the level of engine
coolant by observing the reserve tank.
serious injury.
0000002en
1. With the radiator properly filled, install a cooling

FLYING OBJECT HAZARD! system tester (Figure 8-5, (1)).
injure your eyes.
or moderate injury.
0000003en (1)
0000577A
Figure 8-5
ENGINE COOLANT SYSTEM 2. Apply 10.8 - 14.8 psi (75 - 105 kPa, 0.75 - 1.05
CHECK kgf/cm²) to the cooling system. If the pressure
reading drops, the engine coolant system is
Check the engine coolant system for leakage. leaking. Identify the source of the leak and
repair.

COOLING SYSTEM
DISASSEMBLY OF ENGINE • Remove the drain plug or open the drain cock
(Figure 8-6, (2)) at the lower portion of the
COOLANT PUMP radiator and drain the engine coolant.
Verify the condition of the engine coolant pump
before disassembling it from the engine. Check the
engine coolant pump shaft bearing for abnormal (1)
noise, sticking, excessive play and water leakage.
Replace the coolant pump if any of these conditions
are present.
FULL
LOW
CAUTION
If the engine coolant pump must be
replaced, replace the engine coolant
pump as an assembly only. Do not
attempt to repair the engine coolant
pump or replace individual components. (2) 0000074A
0000041en
Figure 8-6
1. Make sure the engine and engine coolant are • Drain the coolant from the engine block.
not hot. Remove the coolant drain plug
2. Before removing the engine coolant pump or (Figure 8-7, (1)) from the engine block.
thermostat, it will be necessary to drain the
engine coolant. Drain the coolant into a clean
container if the coolant is to be reused.
Otherwise, properly dispose of the coolant.
A WARNING
(1)
BURN HAZARD!
drain the engine coolant. Hot engine
0001578A
• Failure to comply could result in death Figure 8-7
or serious injury. 3. Loosen the V-belt.
0000016en
4. Loosen the alternator mounting bolts and pivot
the alternator out of the way.
• Drain the coolant from the radiator. Remove
the radiator cap (Figure 8-6, (1)).

COOLING SYSTEM
3. Disassemble the mechanical seal
A CAUTION (Figure 8-9, (6)), flange (Figure 8-9, (7)), and
O-ring (Figure 8-9, (8)).
(10)
PINCH HAZARD!
(9)
0000014en (1)
5. Remove the engine coolant fan guard (if (8) (7) (2)
equipped), engine coolant fan (if equipped)
(6) (5)
(Figure 8-8, (2)), spacer (Figure 8-8, (3)), (4) 0001667
(3)
engine coolant pump V-pulley (Figure 8-8, (4))
and V-belt. Figure 8-9
4. Remove the thermostat cover
(5)
(Figure 8-10, (1)). Discard the gasket
(4) (Figure 8-10, (2)).
(3)
(2)
(1)
(2)
(3)
(4)
(1)
0001639A
0001640A
Figure 8-8
Figure 8-10
Disassembly of the 4TNE92-NMHA 5. Remove the thermostat (Figure 8-10, (3)).
Coolant Pump Discard the gasket (Figure 8-10, (4)).
1. Remove the engine coolant pump bolts Disassembly of the 4TNE92-NMH and
(Figure 8-9, (2), (3)). Remove the engine 4TNE98-NMH Coolant Pumps
coolant pump (Figure 8-9, (1)).
1. Remove the engine coolant pump bolts
2. Remove the bolt (Figure 8-9, (9)) holding the (Figure 8-11, (2)). Remove the engine coolant
cover (Figure 8-9, (5)) on the pump. Discard pump (Figure 8-11, (1)). Discard the gasket
the gaskets (Figure 8-9, (4), (10)). (Figure 8-11, (6)).

COOLING SYSTEM
2. Remove coolant pump pipe (Figure 8-11, (3)) CLEANING AND INSPECTION
from engine block. Discard the O-rings
(Figure 8-11, (4)). Thermostat
3. Remove the bolts (Figure 8-11, (5)) holding the
1. Check for proper operation of the thermostat.
cover (Figure 8-11, (7)) on the pump. Discard
Place the thermostat (FIgure 8-13, (1)) and an
the gasket (Figure 8-11, (8)).
accurate thermometer (FIgure 8-13, (2)) in
warm water.
(6)
(2)
(7)
(8)
(1)
(5) (1)
(4) (2)
(4)
(3) 0001701A 0000577A
Figure 8-11 FIgure 8-13

4. Remove the thermostat cover 2. Slowly increase temperature of the water using
(Figure 8-12, (1)). Discard the gasket an external heat source.
(Figure 8-12, (2)). 3. The thermostat is normal if it starts to open at
160°F (71°C) and fully opens at 185°F (85°C).
(1)
Radiator Cap
(2)
(3) 1. Check for proper operation of the radiator cap.
Install the radiator cap (Figure 8-14, (1)) on a
(4)
cooling system tester.
0001702A
(1)
Figure 8-12
0000577A
5. Remove the thermostat (Figure 8-12, (3)).
Discard the gasket (Figure 8-12, (4)). Figure 8-14
2. Apply 10.8 - 14.8 psi (75 - 105 Kpa, 0.75 - 1.05
kgf/cm²) to the radiator cap. The radiator cap
must open within the specified range.

COOLING SYSTEM
ASSEMBLY OF ENGINE
COOLANT PUMP (10)
Assembly of the 4TNE92-NMHA
Coolant Pump
1. Install the thermostat (Figure 8-15, (2)) using a
new O-ring (Figure 8-15, (1)). (9)
(4) (5) (1)

(3)
(8) (7) (2)
(2)
(6) (5)
(1) (4) 0001667
(3)
Figure 8-16
4. Position the engine coolant pump
0001670 (Figure 8-16, (1)) on the engine.
Figure 8-15 5. Install the engine coolant pump bolts. Tighten

the bolts (Figure 8-16, (2), (3)) to the specified
2. Install the thermostat cover (Figure 8-15, (4)) torque.
using a new gasket (Figure 8-15, (3)). Tighten
Assembly of the 4TNE92-NMH and
the thermostat cover bolts (Figure 8-15, (5)) to
the specified torque. 4TNE98-NMH Coolant Pumps
3. Assemble the mechanical seal 1. Install the thermostat (Figure 8-17, (3)) using a
(Figure 8-16, (6), flange (Figure 8-16, (7), new O-ring (Figure 8-17, (4)).
O-ring (Figure 8-16, (8), cover
(Figure 8-16, (5) and new gaskets (1) (5)
(Figure 8-16, (4), (10)).
(2)
(3)
(4)
0001702B
Figure 8-17
2. Install the thermostat cover (Figure 8-17, (1))
using a new gasket (Figure 8-17, (2)). Tighten
the thermostat cover bolts (Figure 8-17, (5)) to
the specified torque.

COOLING SYSTEM
3. Assemble the cover (Figure 8-18, (7) Using a Assembly of All Coolant Pump
new gasket (Figure 8-18, (8)).
Models
6. Install the engine coolant pump V-pulley
(Figure 8-19, (4)), spacer (Figure 8-19, (3))
(6) engine coolant fan (Figure 8-19, (2)) and
engine coolant fan guard (if equipped).
(7)
(8)
(1) (5)
(4)
(5) (3)
(2)
(4) (2)
(4)
(3) 0001701A
Figure 8-18
4. Reinstall the coolant pump pipe
(Figure 8-18, (3)) to the engine coolant pump (1)
using a new O-ring (Figure 8-18, (4)).
0001639A
5. Position the engine coolant pump
(Figure 8-18, (1)) on the engine. Be sure a new Figure 8-19
O-ring (Figure 8-18, (4)) is positioned between
the coolant pump pipe and engine. Install the 7. Install the alternator.
engine coolant pump bolts. Tighten the bolts 8. Inspect the condition of the V-belt. There must
(Figure 8-18, (2)) to the specified torque. be clearance (Figure 8-20, (1)) between the
V-belt and the bottom of the pulley groove. If
there is no clearance (Figure 8-20, (2))
between the V-belt and the bottom of the pulley
groove, replace the V-belt.
(2)
(1)
0000584
Figure 8-20

COOLING SYSTEM
9. Install the V-belt. Tighten the V-belt to the
proper tension. See Check and Adjust Cooling
Fan V-belt on page 5-22.
10. Reinstall and tighten the drain plug or close the
drain cock in the radiator. Reinstall and tighten
the engine block drain plug or reconnect the
coolant hose at the oil cooler.
11. Fill radiator and engine with engine coolant.
See Drain, Flush, and Re-fill the Coolant
System with New Coolant on page 5-35.
CAUTION
remove the cap.
0000006en

COOLING SYSTEM

Section 9
LUBRICATION
SYSTEM
TNE Service Manual
Table of Contents
Page
Oil Pump Service Information.......................................................... 9-5
Lubrication System Diagram ........................................................... 9-6
Checking Engine Oil Pressure ........................................................ 9-7
Oil Pump Components .............................................................. 9-7
Before You Begin Servicing....................................................... 9-7
Disassembly of Oil Pump .......................................................... 9-9
Cleaning and Inspection ............................................................ 9-9
Assembly of Oil Pump ............................................................. 9-11

LUBRICATION SYSTEM

LUBRICATION SYSTEM
procedures necessary to service the Trochoid oil A WARNING
pump.
See Replace Engine Oil and Engine Oil Filter on
page 5-26 for engine oil and engine oil filter
replacement procedures.
BURN HAZARD!
A WARNING • Keep your hands, and other body
SEVER HAZARD! surfaces are extremely hot while the
• Stop the engine before you begin to engine is operating and could
service it. seriously burn you.
• NEVER leave the key in the key switch • Failure to comply could result in death
when you are servicing the engine. or serious injury.
Someone may accidentally start the 0000015en

serious injury. A WARNING
• Failure to comply could result in death EXPOSURE HAZARD!
or serious injury.
0000010en
sealant removers.
or serious injury.
0000014en

LUBRICATION SYSTEM
A CAUTION

injure your eyes.
or moderate injury.
0000003en
CAUTION
engine life.
the cap.
in white exhaust smoke, engine
0000005en
CAUTION
If the oil pump must be replaced, replace
it as an assembly only. Do not replace
individual components
0000030en

LUBRICATION SYSTEM
OIL PUMP SERVICE INFORMATION

Engine Oil Pressure - All Models
Model Number at Rated Engine rpm at Low Idle Speed

4TNE92-NMH 42.06 - 56.57 psi
4TNE92-NMHA (0.29 - 0.39 MPa) 8.5 psi (0.06 MPa, 0.6 kfg/cm2) or greater
4TNE98-NMH (3.0 - 4.0 kgf/cm2)
Outer Rotor Outside Clearance - All Models
Reference
Model Standard Limit
Page
Check Outer
4TNE92-NMH
0.0039 to 0.0061 in 0.0098 in Rotor Outside
4TNE92-NMHA
(0.100 to 0.155 mm) (0.25 mm) Clearance on
4TNE98-NMH
page 9-10
Outer Rotor Side Clearance - All Models
Model Standard Limit Reference Page

Check Outer
4TNE92-NMH
0.0020 to 0.0039 in 0.0059 in Rotor Side
4TNE92-NMHA
4TNE98-NMH
page 9-10
Outer Rotor to Inner Rotor Tip Clearance - All Models

Model Standard Limit Reference Page
Outer Rotor to
4TNE92-NMH
0.0063 in Inner Rotor Tip
4TNE92-NMHA –
(0.16 mm) Clearance on
4TNE98-NMH
page 9-10
Rotor Shaft Clearance - All Models
Reference
Model Inspection Item Standard Limit
Page
0.5110 to 0.5126 in 0.5138 in
Gear Case Bearing I.D.
(12.980 to 13.020 mm) (13.05 mm) Check Rotor
4TNE92-NMH
0.5089 to 0.5106 in 0.5085 in Shaft
4TNE92-NMHA Rotor Shaft O.D.
4TNE98-NMH
0.0004 to 0.0026 in 0.0041 in page 9-10
Rotor Clearance
(0.010 to 0.065 mm) (0.105 mm)

LUBRICATION SYSTEM
LUBRICATION SYSTEM DIAGRAM
Oil Filter
Bypass Valve
Fuel
Injection Pump
Oil Pressure
Switch
Cylinder Body - Main Gallery

Pressure
Regulator Valve
Idle Gear Camshaft Crank
Oil Pump Shaft Bearing Journal
Rocker Arm Crank Pin

Oil Suction Pipe Bearing
Strainer
Rocker Arm
Tappet
Cam Face
Oil Pan
0001624
FIgure 9-1

LUBRICATION SYSTEM
CHECKING ENGINE OIL Oil Pump Components

PRESSURE
Perform an engine oil pressure check if there is any (1)
indication of low oil pressure such as the oil (2)
pressure indicator is on or the oil pressure gauge
indicates low oil pressure. (5)
See Engine Oil Pressure - All Models specifications
on page 9-5 for the engine oil pressure.
(3)
1. Disconnect the connector from the oil pressure
switch (Figure 9-2, (1)). (4) 0000043A
1. Gear Case Housing

2. Outer Rotor
3. Inner Rotor
4. Cover Plate
5. Drive Gear
FIgure 9-3

(1)
CAUTION
0000028B
Figure 9-2
2. Remove the oil pressure switch.
3. Install a mechanical oil pressure gauge in the
oil pressure switch port.
4. Start the engine: training.
• If the mechanical oil pressure gauge indicates • Read and understand this Operation
good oil pressure, replace the faulty oil Manual before you operate the
pressure switch or faulty machine oil pressure machine to ensure that you follow safe
gauge. operating practices and maintenance
• If the mechanical oil pressure gauge indicates procedures.
low oil pressure, troubleshoot the lubrication • Machine safety signs and labels are
system to locate the cause of the low oil additional reminders for safe operating
pressure. See Quick Reference Table For and maintenance techniques.
Troubleshooting 13-6.
0000002en

LUBRICATION SYSTEM
A WARNING A CAUTION
SEVER HAZARD!
• Stop the engine before you begin to FLYING OBJECT HAZARD!
service it.
• NEVER leave the key in the key switch servicing engine and when using
when you are servicing the engine. compressed air or high-pressure
Someone may accidentally start the water. Dust, flying debris, compressed
engine and not realize you are air, pressurized water or steam may
servicing it. This could result in a injure your eyes.
serious injury.
• If you must service the engine while it or moderate injury.
is operating, remove all jewelry, tie 0000003en
from moving / rotating parts. CAUTION
• Failure to comply could result in death • Only use the engine oil specified.
or serious injury. Other engine oils may affect warranty
0000010en
engine life.
A WARNING • Prevent dirt and debris from
the cap.
BURN HAZARD! • NEVER mix different types of engine

• Keep your hands, and other body lubricating properties of the engine oil.
such as the muffler, exhaust pipe, • NEVER overfill. Overfilling may result
turbocharger (if equipped) and engine in white exhaust smoke, engine
block during operation and shortly overspeed or internal damage.
after you shut the engine down. These 0000005en

seriously burn you.
or serious injury.
0000015en

LUBRICATION SYSTEM
Disassembly of Oil Pump
CAUTION
(1)
If the oil pump must be replaced, replace
it as an assembly only. Do not replace
individual components (2)
0000030en
1. Remove the engine coolant fan guard (if

equipped), engine coolant fan (Figure 9-4, (3)),
(3)
spacer (Figure 9-4, (2)), engine coolant pump
V-pulley (Figure 9-4, (1)) and V-belt.
0000049A
Figure 9-5
Cleaning and Inspection

(2) (3)
Wash the oil pump, oil pressure regulator and oil
pump cavity. Inspect for wear or damage. Replace
as necessary.
A CAUTION
If any oil pump component clearance
exceeds its limit, the oil pump must be
replaced as an assembly.
(1)
0000163C 0000015en
Figure 9-4
2. Remove the front crankshaft pulley.
3. Remove the gear case cover (Figure 9-5, (1))
assembly.
4. Remove the oil pump assembly bolts. Remove
the oil pump assembly (Figure 9-5, (2)) from
the gear case housing (Figure 9-5, (3)).

LUBRICATION SYSTEM
Check Outer Rotor Outside Clearance Check Outer Rotor Side Clearance
Determine the outside clearance of the outer rotor. Determine the side clearance of the outer rotor
Insert a feeler gauge between the outer rotor across the pump cavity. Measure the depression
(FIgure 9-6, (1)) and gear case oil pump cavity using a depth micrometer (FIgure 9-8, (1)).
(FIgure 9-6, (2)).
(1)
(1)
(2)
0000045A
FIgure 9-6
See Outer Rotor Outside Clearance - All
Models specifications on page 9-5 for the service 0001615A
limit. FIgure 9-8

Outer Rotor to Inner Rotor Tip Clearance See Outer Rotor Side Clearance - All
Determine the outer rotor to inner rotor tip Models specifications on page 9-5 for the service
clearance. Insert a feeler gauge between the top of limit.
an inner rotor tooth (Figure 9-7, (1)) and the top of
an outer rotor tooth (Figure 9-7, (2)) and measure
Check Rotor Shaft Clearance
the clearance. Determine the rotor shaft clearance. Measure the
outside diameter of the rotor shaft (FIgure 9-9, (1))
See Outer Rotor to Inner Rotor Tip and the bore diameter in the gear case housing
Clearance specifications on page 9-5 for the (FIgure 9-9, (2)).
service limit.
Calculate the difference between the two
measurements to determine the clearance.
(1)
(2) (1)
0001153A
Figure 9-7 (2)

0000047A
FIgure 9-9

LUBRICATION SYSTEM
See Rotor Shaft Clearance - All 4. Thoroughly clean all old sealant from the gear
Models specifications on page 9-5 for the service case cover (Figure 9-11, (3)) and gear case
limits. housing (Figure 9-11, (2)). Apply ThreeBond
Liquid Gasket, Yanmar Part No. 977770-01212,
Assembly of Oil Pump or equivalent sealant to the gear case cover.
1. Lubricate the outer rotor and pump bore in the Install the gear case cover housing. Tighten the
gear case. cover bolts to the specified torque.
2. Install the outer rotor in the gear case housing. 5. Install the crankshaft pulley.
Punch mark (Figure 9-10, (1)) on end of the 6. Install the engine coolant pump V-pulley
outer rotor must face away from the gear case (Figure 9-12, (1)), spacer (Figure 9-12, (2)),
housing (Figure 9-10, (2)). engine coolant fan (Figure 9-12, (3)) and
engine coolant fan guard (if equipped).
2
(2) (3)
1
0000048A
Figure 9-10
3. Install the oil pump assembly (Figure 9-11, (1))
into the gear case housing (Figure 9-11, 2). (1)
0000163C
Tighten the bolts to specified torque.
Figure 9-12
7. Install the V-belt. Tighten the V-belt to the
(3) Fan V-belt on page 5-22.
(1)
(2)
0000049C
Figure 9-11

LUBRICATION SYSTEM

Section 10
STARTER MOTOR
TNE Service Manual
Table of Contents
Page
Starter Motor Service Information ................................................. 10-5
Starter Motor Troubleshooting....................................................... 10-6
Starter Motor Precautions ............................................................. 10-7
Starter Motor Servicing.................................................................. 10-8
Starter Motor Components ...................................................... 10-8
Before You Begin .................................................................... 10-9
Starter Motor Removal .......................................................... 10-10
Starter Motor Disassembly .................................................... 10-10
Inspection .............................................................................. 10-12
Starter Motor Assembly ......................................................... 10-18
No Load Test ......................................................................... 10-20
Starter Motor Installation ....................................................... 10-20

STARTER MOTOR

STARTER MOTOR
servicing of the 4TNE92-NMH, 4TNE92-NMHA, A WARNING
and 4TNE98-NMH starter motors.
A WARNING
SHOCK HAZARD!
SEVER HAZARD!
• Stop the engine before you begin to electrical system.
service it.
• NEVER leave the key in the key switch cracks, abrasions, and damaged or
when you are servicing the engine. corroded connectors. ALWAYS keep
Someone may accidentally start the the connectors and terminals clean.
or serious injury.
serious injury.
0000009en
other body parts and clothing away A WARNING
or serious injury.
0000010en
EXPOSURE HAZARD!
sealant removers.
or serious injury.
0000014en

STARTER MOTOR
A CAUTION

injure your eyes.
or moderate injury.
0000003en
CAUTION
The starter motor can be damaged if
operated continuously longer than 30
seconds while performing the no load
test.
0000034en

STARTER MOTOR
STARTER MOTOR SERVICE INFORMATION

Hitachi Model Number S13-204
Yanmar Part Number 129900-77010
Nominal Output 3.0 HP (2.3 kW)
Weight 12.1 lbs (5.5 kg)
Revolution Direction (As Viewed From Pinion) Clockwise
Engagement System Magnetic Shift
Terminal Voltage / Current 11 V / 140 A max
No-load
Revolution 4100 rpm min
Terminal Voltage / Current 2.5 V / 1050 A max
Loaded 18.1 ft lbs (24.5 N·m,
Torque
2.5 kgf·m) min
Clutch System Overrunning
Pinion Projection Voltage at 212°F (100°C) 8.6 V max
Pinion DP or Module / Number of Teeth M3 / 9
Difference (O-ring, Oil Seal) Dry (none)
Application Standard
Spring Force 7.868 lbf (35 N, 3.6 kgf)
Brush Standard 0.591 in (15 mm)
Height
Limit 0.354 in (9 mm)
Series Coil Resistance 0.27 Ω at 68°F (20°C)
Magnetic Switch
Shunt Coil Resistance 0.60 Ω at 68°F (20°C)
Standard 1.437 in (36.5 mm)
Outside Diameter
Limit 1.398 in (35 mm)
Commutator Run-Out
Limit 0.008 in (0.2 mm)
Standard 0.020 - 0.031 in (0.5 - 0.8 mm)
Insulation Depth
Limit 0.008 in (0.2 mm)
Armature Run-Out
Limit 0.008 in (0.02 mm)
Armature Front 6903DDU
Armature Rear 608DDU
Bearing Type Nominal Number
Pinion Front 60004DDU
Pinion Rear 6904DDU
Pinion Projection Length (Length L) 0.012 - 0.059 in (0.3 - 1.5 mm)

10-6
Is the shift lever at NO Move shift lever to Is battery fully charged NO • Charge or replace battery.
NEUTRAL position? NEUTRAL position. and terminals clean? • Clean terminals.
YES
Engine does not start? Inspect wiring up to magnetic switch
Is starter motor magnetic and repair if necessary.
NO • Key switch
switch actuating sound
STARTER MOTOR
YES heard? • Safety relay

• Magnetic switch assembly
NO NO • Electrical connections
Does engine crank? Is starter motor operating? YES
YES
• Adjust / pinion projection length.
• Inspect shift lever for deformation,
Pinion and ring gear NO return spring for fatigue and pinion
meshing normal? for sliding.
YES • Repair meshing between pinion and
ring gear or replace as needed..
YES
Connect M terminal of starter NO • Inspect brush and replace if worn.
Pinion roller clutch or motor directly to battery. • If brushes are not worn, replace armature
reduction gear damaged. Does starter motor operate? assembly.
Inspect and replace.
YES
Magnetic switch assembly If starter motor becomes wet,replace magnetic switch

contact defective. Repair assembly even if function is normal.
STARTER MOTOR TROUBLESHOOTING
NO or replace.
(slow revolution) NO
Is revolution normal? Is battery fully charged • Charge or replace battery. If a problem occurs:
and terminals clean? • Clean terminals. Immediately disconnect battery negative terminal.
YES YES
Inspect fuel system. Is the engine oil NO Engine does not stop
Replace engine oil.
viscosity correct? even when key switch is
turned OFF.
YES
TNE Service Manual

Does engine turn when YES Repair or replace Repair or replace key switch, starting
starter motor is replaced? starter motor. motor relay or magnetic switch assembly.
Slow Revolution
Inspect condition of engine.
0000102
STARTER MOTOR
STARTER MOTOR
PRECAUTIONS
Failure to follow these precautions may result in a
loss of warranty coverage on a related item. Make
sure that all users read and understand these
precautions.
CAUTION
Make sure that the combined total
resistance of the battery cable in both
directions between the starter motor
and the battery is within the value
indicated on the wiring diagram. The
starter motor will malfunction or break
down if the resistance is higher than the
specified value.
0000054en
CAUTION
The starter motor is water-proofed
according to JIS D 0203, R2 which
protects the motor from rain or general
cleaning. Do not use high-pressure
wash or submerse the starter motor in
water.
0000055en
CAUTION
Use a specialized battery charger to
recharge a battery with a voltage of 8
Volts or less. Booster starting a battery
with a voltage of 8 Volts or less, will
generate an abnormally high voltage
and destroy electrical equipment.
0000056en

STARTER MOTOR
STARTER MOTOR SERVICING

Starter Motor Components
(13)
(12) (14)
(11)
(10)
(9)
(8)
(7)
(6)
(5)
(4)
(23)
(3)
(2)
(1) (15)
(18)
(22)
(21)
(19)
(20)
(17)
(16) 0000103A
FIgure 10-1
1. Pinion Shaft 9. Shift Lever 16. Armature Assembly
2. M4 Bolts (3) 10. Torsion Spring 17. Field Coil Assembly
3. Bearing Retainer 11. Plunger 18. Positive (+) Brushes
4. Pinion Clutch Assembly 12. Dust Covers (Shims) 19. Negative (-) Brushes
5. Return Spring 13. Magnetic Switch 20. Brush Holder Assembly
6. Pinion Stop Assembly 21. Rear Cover
7. Retaining Ring 14. Cover 22. M5 Through Bolts (2)
8. Gear Housing 15. M6 Bolts (2) 23. M4 Bolts (2)

STARTER MOTOR
Before You Begin
A WARNING
A WARNING
SHOCK HAZARD!
SEVER HAZARD! • Turn off the battery switch (if
• Stop the engine before you begin to equipped) or disconnect the negative
service it. battery cable before servicing the
• NEVER leave the key in the key switch electrical system.
when you are servicing the engine. • Check the electrical harnesses for
Someone may accidentally start the cracks, abrasions, and damaged or
engine and not realize you are corroded connectors. ALWAYS keep
servicing it. This could result in a the connectors and terminals clean.
serious injury.
• If you must service the engine while it or serious injury.
is operating, remove all jewelry, tie 0000009en
from moving / rotating parts. A WARNING
or serious injury.
0000010en
EXPOSURE HAZARD!
sealant removers.
or serious injury.
0000014en

STARTER MOTOR
3. Remove the two M12 bolts (Figure 10-2, (1))
A CAUTION retaining the starter motor to the gear case.
Remove the starter motor from the gear case.
(1)

0000253A
injure your eyes.
or moderate injury.
0000003en
Figure 10-2
Starter Motor Removal Starter Motor Disassembly

1. Loosen the M8 nut from the magnetic switch
A WARNING assembly. Disconnect the wire from the
magnetic switch.
SHOCK HAZARD!
electrical system.
cracks, abrasions, and damaged or 0000104
the connectors and terminals clean. Figure 10-3
• Failure to comply could result in death 2. Remove the two M4 bolts (Figure 10-4, (1))
or serious injury. securing the rear cover (Figure 10-4, (2)) to the
0000009en
brush holder assembly (Figure 10-4, (3)).
1. Disconnect the battery cables at the battery.

2. Remove the electrical wires from the magnetic
switch assembly.

STARTER MOTOR
(7) (1)
(4)
(1)
(2) (3)
0000107A
Figure 10-6
(6) (5) (3) (2) 6. Pull the armature assembly (Figure 10-6, (3))
0000105A
out from the field coil assembly
Figure 10-4 (Figure 10-6, (2)).
3. Remove the two M5 through bolts 7. Remove the two M6 bolts (Figure 10-7, (1))
(Figure 10-4, (4)). Separate the rear cover retaining the magnetic switch assembly
(Figure 10-4, (2)), field coil assembly (Figure 10-7, (2)) to the gear housing. Remove
(Figure 10-4, (5)) with the armature assembly the magnetic switch assembly, dust cover(s)
(Figure 10-4, (6)) from the gear housing (Figure 10-7, (3)) and torsion spring
(Figure 10-4, (7)). (Figure 10-7, (4)) from the gear housing.
4. Pull the brush springs up using a brush spring (1)
puller. On the negative (-) side, bring the brush
spring into contact with the side of the brush for
lifting from the commutator surface. On the
positive (+) side, remove the brush from the (2) (4)
brush holder assembly (Figure 10-5, (1)).
(3)
0000108A
Figure 10-7
8. Disassemble the dust cover (Figure 10-8, (3))
and shift lever (Figure 10-8, (4)) from the gear
(1) housing.
0000106A
(1)
Figure 10-5
5. Remove the brush holder assembly
(Figure 10-6, (1)) from the armature assembly
(Figure 10-6, (3)).
(2)
0000109A
Figure 10-8

STARTER MOTOR
9. Remove the three M4 bolts (Figure 10-9, (1))
(4)
securing the bearing retainer assembly (1)
(Figure 10-9, (2)) to the gear housing. Remove
the bearing retainer assembly from the gear (5)
housing. (2)
(3)
(2)
0000112A
Figure 10-11
(3)
Inspection
Armature
Commutator Surface Inspection
(1)
0000110A If the commutator surface is rough, polish the
surface with #500 to #600 emery cloth.
Figure 10-9
10. Remove the pinion clutch assembly
(Figure 10-9, (3)) from the bearing retainer
assembly.
11. Using a flat-blade screwdriver, remove the
retaining ring (Figure 10-10, (1)) from the shaft
of the pinion.
(1)
0000117
Figure 10-12
0000111A
Figure 10-10
12. Disassemble the pinion stop
(Figure 10-11, (3)), return spring
(Figure 10-11, (4)), pinion clutch assembly
(Figure 10-11, (1)), and pinion shaft
(Figure 10-11, (5)).

STARTER MOTOR
Measure Commutator Outside Diameter
(3)
Measure the commutator outside diameter.
Replace the armature if the measurement is less
than the limit.
(2)
(1)
(5) (4)
0000118
0000113
Figure 10-14
Figure 10-13
Standard Limit
Standard Limit
0.020 - 0.031 in 0.008 in
1.437 in 1.378 in (0.5 - 0.8 mm) (0.2 mm)
(36.5 mm) (35 mm)
Armature Coil Continuity Test
Measure Commutator Insulation Depth
Check for continuity between the commutator
Measure the depth of the insulating material segments using a multimeter. The multimeter
(Figure 10-14, (1)) between commutator segments should indicate continuity.
(Figure 10-14, (2)). If the depth measures less
than the limit, use a hacksaw blade If the multimeter does not indicate continuity,
(Figure 10-14, (3)) to remove the insulating replace the armature.
material until the depth is within the limit.
A normal commutator condition is indicated in
(Figure 10-14, (4)). An abnormal commutator
condition is indicated in (Figure 10-14, (5)).
0000114
Figure 10-15

STARTER MOTOR
Armature Coil Insulation Test Field Coil
Check for continuity between a commutator
Field Coil Continuity Test
segment and the shaft or armature using a
multimeter. The multimeter should not indicate Check for continuity between the field coil terminals
continuity. using a multimeter. The multimeter should indicate
continuity.
If the multimeter indicates continuity, replace the
armature. If the multimeter does not indicate continuity,
replace the field coil assembly.
0000115
Figure 10-16
Measure Armature and Commutator Run-Outs 0000119
Measure the armature core run-out and the Figure 10-18

commutator run-out using a dial indicator. Replace
the armature if either of the measurements is less Field Coil Insulation Test
than the limit. Check for continuity between field coil terminal and
yoke using a multimeter. The multimeter should not
indicate continuity.
field coil assembly.
0000116
FIgure 10-17
Standard Limit
0.001 in 0.008 in
Armature
(0.03 mm) (0.2 mm)
0000120
0.001 in 0.008 in
Commutator
(0.03 mm) (0.2 mm) Figure 10-19

STARTER MOTOR
Measure Brush Length Brush Spring Test
Measure the length of the brush. Replace the brush Test the spring force for each brush spring. Replace
if the length is less than the limit. the brush spring if the force is not within the range.
0000123
0000121
Figure 10-22
FIgure 10-20
Standard
Standard Limit 6.969 - 8.758 lbf
0.591 in 0.354 in (31 - 39 N, 3.1 - 3.9 kgf)
(15 mm) (9 mm)
Brush Holder
Brush Holder Insulation Test
Check for continuity between each brush holder
and the base using a multimeter. The multimeter
should not indicate continuity.
brush holder.
0000122
Figure 10-21

STARTER MOTOR
Magnetic Switch Series Coil Continuity Test
If the starter motor becomes wet, replace the Check for continuity between the “S” and “M”
magnetic switch even if the magnetic switch terminals using a multimeter. The multimeter
assembly function is normal. should indicate continuity.
Shunt Coil Continuity Test If the multimeter does not indicate continuity,
replace the magnetic switch.
Check for continuity between the “S” terminal and
the switch body using a multimeter. The multimeter
should indicate continuity.
If the multimeter does not indicate continuity,
0000125
Figure 10-24
Coil Resistance Test

0000124
Test Resistance at 68°F (20°C)
FIgure 10-23 Series Coil 0.27 Ω
Shunt Coil 0.6 Ω

STARTER MOTOR
Contact Continuity Test Slide the pinion clutch assembly on the shaft. It
Depress the plunger at the bottom of the magnetic should slide smoothly on the shaft. Rust, too much
switch. Check for continuity between the “B” and grease or damage could prevent the pinion clutch
“M” terminals using a multimeter. The multimeter from sliding smoothly. If the pinion clutch assembly
should indicate continuity. does not slide smoothly, clean the shaft and pinion
clutch assembly or replace the damaged
If the multimeter does not indicate continuity, component.
0000128
Figure 10-27
0000126
Ball Bearing Inspection
Rotate each ball bearing while holding the pinion
Figure 10-25
clutch assembly. Replace the ball bearing if it does
Pinion Clutch Assembly not rotate smoothly or has excessive play.
Pinion Clutch Assembly Inspection

Manually rotate the pinion clutch assembly in the
drive direction. It should rotate freely in the drive
direction and locked in the opposite direction.
Replace the pinion clutch assembly if the results
are different.
0000129
Figure 10-28
0000127
Figure 10-26

STARTER MOTOR
Starter Motor Assembly 5. Assemble the magnetic switch assembly to the
gear housing. Pry the pinion away from the
1. Apply NPC-FC6A grease to the pinion shaft. gear housing to allow installation of the
Assemble the pinion shaft (FIgure 10-29, (5)), magnetic switch assembly.
pinion clutch assembly (FIgure 10-29, (1)),
return spring (FIgure 10-29, (4)) and pinion
stop (FIgure 10-29, (3)). Install the retaining
ring (FIgure 10-29, (2)) in groove in the pinion
shaft. Slide the piston stop over the retaining
ring.
(4)
(1)
(5)
0000131
(2)
Figure 10-31
(3)
6. Secure the magnetic switch assembly to the
0000112A
gear housing using the two M6 bolts.
FIgure 10-29 7. Carefully install the armature assembly
2. Install the pinion clutch assembly into the (Figure 10-32, (1)) into the field coil assembly
bearing retainer assembly. (Figure 10-32, (2)).
3. Install the bearing retainer assembly and pinion
assembly to the gear housing. Install and (1)
tighten the three M4 bolts.
4. Apply NFC-F6A grease to the sliding portions of
the shift lever (FIgure 10-30, (1)). Assemble the
torsion spring (FIgure 10-30, (2)), shift lever
and dust cover(s) (FIgure 10-30, (3)), plunger
(FIgure 10-30, 4) and magnetic switch (2)
assembly (FIgure 10-30, (5)). 0000269
(3) Figure 10-32
(2)
(1)
(5)
(4)
0000268
FIgure 10-30

STARTER MOTOR
8. Position the brush springs in brush holders. Check Pinion Projection Length
Install the brushes in the brush holders. 1. Connect the positive (+) lead from a battery to
Reversing the brushes in will cause the starter the “S” terminal.
motor to turn backwards.
2. Connect the negative (-) lead to the “M”
terminal.
3. Lightly pull the pinion out away from the gear
housing.
4. Turn the switch ON and measure the pinion
moving distance L in the thrust direction.
Perform this test within 10 seconds.
0000106
FIgure 10-33
9. Carefully install the brush holder assembly to
the armature assembly.
10. Install the field coil assembly with the armature
assembly to the gear housing. 0000132
11. Install the rear cover to the brush holder Figure 10-35
assembly. Securely tighten the two bolts.
Standard
12. Install the two M4 through bolts. Tighten the
through bolts to the specified torque. L 0.012 - 0.059 in (0.3 to 1.5 mm)
13. Connect the wire to the magnetic switch
5. If the measured L dimension is outside the
assembly. Tighten the M8 nut. Install the cover
standard range, adjust the dust covers to obtain
over the connection.
the standard range. Dust covers
(Figure 10-36, (1)) are available in 0.020 in (0.5
mm) and 0.031 in (0.8 mm) thicknesses.
(1)
0000104
Figure 10-34
0000133
Figure 10-36

STARTER MOTOR
No Load Test Terminal Voltage / Current 11 V / 140 A max
Test the characteristics of the starter motor by Revolution 4100 rpm min
performing a no load test.
Starter Motor Installation
CAUTION 1. Install the starter motor to the gear case.
The starter motor can be damaged if 2. Install the two M12 bolts (FIgure 10-38, (1)).
operated continuously longer than 30 Tighten the bolts to the specified torque.
seconds while performing the no load
test. (1)
0000034en
1. Secure the starting motor in a vise or other

suitable fixture.
2. Connect an ammeter (FIgure 10-37, (1)) in
series with the battery positive (+) terminal
(FIgure 10-37, (2)) and the “S” terminal
(FIgure 10-37, (3)) of the starter motor
solenoid.
0000253A
3. Connect a voltmeter (FIgure 10-37, (4))
between the solenoid “M” terminal and the
FIgure 10-38
frame of the starter motor.
4. Attach a tachometer in the current or hold a 3. Reconnect the electrical wires to the magnetic
vibration tachometer against the starter motor. switch assembly. Be sure to place the cover
over the battery positive (+) cable connection.
5. Attach a switch in the current.
4. Reconnect the battery cables at the battery.
6. Turn the switch to the ON position. Observe the
starter rpm, amperage draw and voltage
readings. See no load specifications in the
chart below.
(2)
(3) (1)
(4)
0000134
FIgure 10-37

Section 11
ALTERNATOR
TNE Service Manual
Table of Contents
Page
Alternator Service Information....................................................... 11-6
Alternator Troubleshooting ............................................................ 11-7
Alternator Precautions................................................................... 11-8
Alternator Components ................................................................. 11-9
Alternator Servicing ..................................................................... 11-10
Before You Begin Servicing................................................... 11-10
Removal of Alternator............................................................ 11-11
Disassembly of Alternator...................................................... 11-12
Inspection .............................................................................. 11-15
Assembly of Brush Holder ..................................................... 11-20
Assembly of Alternator .......................................................... 11-22
Installation of Alternator......................................................... 11-23
Bench Test ............................................................................ 11-24

ALTERNATOR

ALTERNATOR
servicing of the alternator. A WARNING
A WARNING
SHOCK HAZARD!
SEVER HAZARD!
• Stop the engine before you begin to battery cable before servicing the
service it. electrical system.
• NEVER leave the key in the key switch • Check the electrical harnesses for
when you are servicing the engine. cracks, abrasions, and damaged or
Someone may accidentally start the corroded connectors. ALWAYS keep
engine and not realize you are the connectors and terminals clean.
serious injury.
or serious injury.
• If you must service the engine while it 0000009en
other body parts and clothing away A WARNING
or serious injury.
0000010en
BURN HAZARD!
• Keep your hands, and other body
seriously burn you.
or serious injury.
0000015en

ALTERNATOR
A WARNING A CAUTION
EXPOSURE HAZARD! PINCH HAZARD!

• Always read and follow safety related Carefully rotate the alternator toward the
precautions found on containers of cylinder block while loosening the
hazardous substances like parts V-belt. Failure to comply may result in
cleaners, primers, sealants, and minor or moderate injury.
sealant removers. 0000014en

or serious injury. CAUTION
0000014en
A CAUTION
training.
Manual before you operate the
FLYING OBJECT HAZARD! machine to ensure that you follow safe
• ALWAYS wear eye protection when operating practices and maintenance
servicing engine and when using procedures.
compressed air or high-pressure • Machine safety signs and labels are
water. Dust, flying debris, compressed additional reminders for safe operating
air, pressurized water or steam may and maintenance techniques.
injure your eyes.
• Failure to comply may result in minor engine dealer or distributor for
or moderate injury. additional training.
0000003en 0000002en
CAUTION
Do not remove the positive (+) battery
cable from alternator terminal B while
the engine is operating. Damage to the
alternator will result.
0000037en

ALTERNATOR
CAUTION
Do not reverse the positive and negative
ends of the battery cable. The alternator
diode and stator coil will be damaged.
0000050en
CAUTION
When the battery indicator goes out, it
should not come on again. The battery
indicator only comes on during
operation if the alternator fails or if the
V-belt breaks. However, if an LED is
used in the battery indicator, the LED
will shine faintly during normal
operation.
0000051en
CAUTION
Using a non-specified V-belt will cause
inadequate charging and shorten the
belt life. Use the specified belt.
0000052en
CAUTION
Agricultural or other chemicals,
especially those with a high sulfur
content, can adhere to the IC regulator.
This will corrode the conductor and
result in battery over-charging (boiling)
and charging malfunctions. Consult
Yanmar before using the equipment in
such an environment or the warranty is
voided.
0000053en
CAUTION
Do not use a high pressure wash
directly on the alternator. Water will
damage the alternator and result in
inadequate charging.
0000049en

ALTERNATOR
ALTERNATOR SERVICE INFORMATION

Yanmar Part Number 1198254-77200
Rating Continuous
Battery Voltage 12 Volts
Nominal Output (12 Volts Heat) 60 Amps
No Load Test Maximum rpm 1300 rpm (min-¹)
Output Test Minimum Current (Cool) 13.5 V@ 5000 rpm (min-1)
Grounding Characteristics Negative (-) Side of Circuit
Direction of Revolution (Viewed from Pulley) Clockwise
Rotor Coil Resistance 2.9 Ohms
Outside Diameter of Pulley 2.7 in (69.2 mm)
Brush Length
Limit 0.33 in (8.4 mm)

Turn key switch ON. OFF Disconnect harness L terminal Ground drive machine side OFF Replace the battery indicator.
Does battery indicator and IG terminal at alternator L terminal. Does battery Battery indicator is available from
turn ON? indicator turn on? driven machine manufacturer.
ON ON Inspect rotor assembly and

brushes.
Start Engine.
Inspect or replace V-belt.
TNE Service Manual

Battery indicator ON. Inspect alternator.
At idle, does battery Battery indicator flashes. Inspect diode positive (+) side.
indicator turn OFF?
Battery indicator
OFF is dim.
Increase engine speed to
1500 rpm. Turn light switch ON.
ALTERNATOR TROUBLESHOOTING
Battery voltage minus

L terminal voltage is Excessive voltage drop between
greater than 0.5 volt. BAT and batt ( + side) terminal.
Does battery indicator Battery indicator With engine idling,
come ON? is dim. measure voltage at L

terminal and at battery.
Battery voltage minus Check condition of L terminal.
L terminal voltage is Inspect diode negative (-) side.
OFF less than 0.5 volt.
With engine running at 1500
rpm, measure voltage at Battery voltage greater
than 15.5 volts. Replace regulator.
battery.
Battery voltage
is between 13 With engine idling, Does battery indicator ON Inspect auxiliary diode.
and 15 volts. turn light switch ON. come ON?
OFF
Notes: Not abnormal.
1) Use a fully charged battery
2) DC voltmeter: 0 to 30 V, 0.5 class
3) The check method is also applicable to the bench test 0001666
ALTERNATOR
11-7
ALTERNATOR
ALTERNATOR PRECAUTIONS CAUTION

Failure to follow these precautions may result in a Agricultural or other chemicals,
loss of warranty coverage on a related item. Make especially those with a high sulfur
sure that all users read and understand these content, can adhere to the IC regulator.
precautions. This will corrode the conductor and
result in battery over-charging (boiling)
CAUTION and charging malfunctions. Consult
Do not turn the battery switch OFF while Yanmar before using the equipment in
the engine is operating. Damage to the such an environment or the warranty is
alternator will result. voided.
0000053en
0000038en
CAUTION
Do not reverse the positive and negative
ends of the battery cable. The alternator
0000050en
CAUTION
When the battery indicator goes out, it
should not come on again. The battery
indicator only comes on during
operation if the alternator fails or if the
V-belt breaks. However, if an LED is
operation.
0000051en
CAUTION
Using a non-specified V-belt will cause
inadequate charging and shorten the
belt life. Use the specified belt.
0000052en
CAUTION
0000049en

ALTERNATOR
ALTERNATOR COMPONENTS
12
11
10
9
6 8
5
7
2 3
23
1 27
19 22
20
21
13 25 26
24
18
17
16
0001671A
15
14
Figure 11-1
1. Nut 15. Bolt (2)
2. Pulley 16. Holder
3. Collar 17. IC Regulator Assembly
4. Front Frame Housing 18. Bolt (2)
5. Stator Assembly 19. Nut
6. Stud (2) 20. Insulation Bushing
7. Front Frame Housing Bearing 21. Bolt
8. Bearing Cover 22. Spring (2)
9. Bearing Cover Bolt (4) 23. Brush Holder
10. Rotor Assembly 24. Brush (2)
11. Rear Frame Housing Bearing 25. Bolt
12. Thrust Washer 26. Rear Cover
13. Nut (2) 27. Bolt (3)
14. Rear Frame Housing

ALTERNATOR
ALTERNATOR SERVICING
A WARNING
A WARNING
BURN HAZARD!
• Keep your hands, and other body
SEVER HAZARD! such as the muffler, exhaust pipe,
• Stop the engine before you begin to block during operation and shortly
service it. after you shut the engine down. These
• NEVER leave the key in the key switch surfaces are extremely hot while the
when you are servicing the engine. engine is operating and could
Someone may accidentally start the seriously burn you.
engine and not realize you are • Failure to comply could result in death
servicing it. This could result in a or serious injury.
serious injury.
0000015en

back long hair, and keep your hands, A WARNING
or serious injury.
0000010en
EXPOSURE HAZARD!
sealant removers.
or serious injury.
0000014en

ALTERNATOR
Removal of Alternator
A CAUTION l
A WARNING

SHOCK HAZARD!
servicing engine and when using • Turn off the battery switch (if
compressed air or high-pressure equipped) or disconnect the negative
water. Dust, flying debris, compressed battery cable before servicing the
air, pressurized water or steam may electrical system.
injure your eyes. • Check the electrical harnesses for
• Failure to comply may result in minor cracks, abrasions, and damaged or
or moderate injury. corroded connectors. ALWAYS keep
0000003en
CAUTION or serious injury.
0000009en
CAUTION
NEVER permit anyone to operate the damage the alternator and result in
engine or driven machine without proper inadequate charging.
training. 0000049en

Manual before you operate the 1. Disconnect the electrical wires from the
machine to ensure that you follow safe alternator.
operating practices and maintenance 2. Loosen the V-belt.
procedures.
• Machine safety signs and labels are
and maintenance techniques.
0000002en

ALTERNATOR
A CAUTION
(2)
(1)
PINCH HAZARD! 0001673A
Carefully rotate the alternator toward the Figure 11-3

V-belt. Failure to comply may result in 2. Remove the three bolts (Figure 11-4, (1))
minor or moderate injury. retaining the rear cover (Figure 11-4, (2)) to the
0000014en
rear frame assembly and the nut securing
terminal B.
3. Remove the V-belt adjuster to alternator bolt
(Figure 11-2, (1)).
4. Remove the nut (Figure 11-2, (2)) and bolt (3)
(Figure 11-2, (3)) from the gearcase. Remove (1)
the alternator.
(1)
(4) (2)
(5)
0001674A
Figure 11-4
3. Remove the brush holder (Figure 11-4, (3)).
Remove the brush springs (Figure 11-4, (4))
(2) (3) and brushes (Figure 11-4, (5)).
4. Remove the three bolts retaining the regulator
0001672A
assembly (Figure 11-5, (1)) to the holder
(Figure 11-5, (2)).
Figure 11-2
Disassembly of Alternator
1. Remove the nut (Figure 11-3, (1)) from the
shaft of the rotor assembly. Remove the pulley
(Figure 11-3, (2)).

ALTERNATOR
(3)
(4)
(2)
(1)
(1)
(2) 0001676A
Figure 11-6
0001675A
8. Before disassembling the stator from the front
Figure 11-5 frame housing, scratch a positioning line
(Figure 11-7, (3)) on the housing in alignment
Note: Retain the bolts for reassembly. with the lead wire (Figure 11-7, (1)) positioning.
Make sure that the positioning line does not
CAUTION deviate more than ± 0.02 in (± 0.5 mm).
If bolts of incorrect length are used for If installing a new stator, align the new stator with
reassembly, the bolts may contact the the old stator position mark (Figure 11-7, (3)).
rear frame which will cause loss of Make sure that the new and old stator positioning
regulator control. An excessive amount lines do not deviate more than ± 0.02 in
of voltage could be applied to the (± 0.5 mm).
battery, resulting in serious battery
malfunction. (1)
5. Remove the bolts retaining the holder

(Figure 11-5, (2)) to the rear frame housing.
Remove the holder.
6. Remove the nuts (Figure 11-5, (3)) retaining
the insulation bushing (Figure 11-5, (4)).
Remove the insulation bushing.
CAUTION (2)
Be careful not to stretch the stator wires (3)
0001773
when removing the bushing. Damage to
the stator can result. Figure 11-7
7. Remove the four bolts (Figure 11-6, (1)) and 9. If replacing the front frame housing, scratch two
four nuts (Figure 11-6, (2)) securing the rear positioning lines (Figure 11-8, (1)) on the stator
frame housing to the front frame housing. before disassembly. Make sure that the
positioning lines do not deviate more than
± 0.04 in (± 1 mm). If positioning deviates, the
stator lead wire cannot be connected to the
rectifier.

ALTERNATOR
10. Using a press, remove the rotor assembly
(Figure 11-9, (1)) from the front frame housing
(Figure 11-9, (2)) and rear frame housing
(Figure 11-10, (1)).
0001774
(1)
Figure 11-8 (3)
(1)
(2)
0001677A
Figure 11-9
CAUTION
Be careful not to drop the rotor. Damage
to the slip rings or fan can result.
11. Remove the stator assembly

(Figure 11-10, (1)) from the front frame
housing.
(4)
(3)
(2)
(1)
0001678A
Figure 11-10
12. If necessary to replace the bearing
(Figure 11-10, (2)) in the front frame housing,
remove the four bolts (Figure 11-10, (3))
securing the plate (Figure 11-10, (4)) to the
front frame housing. Remove the plate. Use a
puller to remove the bearing. Discard the
bearing.

ALTERNATOR
13. If necessary to replace the bearing Stator Coil Insulation Test
(Figure 11-11, (1)) in the rear frame housing, Check the insulation between the coil terminal and
use a puller to remove. Discard the bearing and the core using a 500 V Megger tester
thrust washer (Figure 11-11, (2)). (Figure 11-13, (1)).
Standard Value 0.1Ω or more
(2)
(1)
0001679A
Figure 11-11
Inspection
Stator Coil
Stator Coil Continuity Test 0001760
(1)
Measure the resistance value at each of the coil
terminals using a multimeter (Figure 11-12, (1)). Figure 11-13
Standard Value 1Ω or less

Rotor
Slip Ring Surface Inspection
If the slip ring surfaces are rough or dirty, polish the
surfaces with #300 to #500 emery cloth.
(1)
0001759
Figure 11-12
0001762
Figure 11-14

ALTERNATOR
Slip Ring Resistance Test Rectifier
Measure the resistance value at the slip rings using Check for continuity using a multimeter set in the
a multimeter. K range (Figure 11-16, (3)).
Standard Value 1Ω or less

CAUTION
Slip Ring Insulation Test NEVER use a 500 V Megger tester to test
the rectifiers. The rectifier will be
Check the insulation between the rotor core
destroyed.
(Figure 11-15, (1)) and the slip rings
(Figure 11-15, (2)) using a 500 V Megger tester Continuity should only exist in one direction.
(Figure 11-15, (3)).
Standard Value 0.1Ω or more
(1)
(1)
(2)
(2)
(3)
(3) 0001761
Figure 11-15
Slip Ring Diameter Inspection

Measure the outer diameter of the rotor slip rings.
0001763
Standard Value 0.567 in (14.4 mm) Figure 11-16

Replacement 0.551 in (14.0 mm)
Standard Item Description
1 Circuit
2 Inspection
CAUTION
The rectifier cannot be judged good or
bad based solely on the correct
direction resistance value. Judgement is
made according to the high and low
resistance values.

ALTERNATOR
IC Regulator
The following instructions are for the M1 type IC regulator.
Wiring Diagram
L112V3.4V
(Charge Light
Substitute)
Terminal E
0001775
L312V3.4W (Electrothermal
(Reverse Side of the IC Regulator)
Choke Substitute)
Figure 11-17
Work Procedures and OK/NG Judgement Standards
No. Procedure Voltage Indicator Remarks

1 Connection
2 Set the variable DC power supply to 12 V. Set SW1 and SW2 to OFF and SW3 to ON.
3 Turn SW1 ON (key switch ON). 12 V L1: ON. Charge light ON.
L2: ON Initial excitation.
dimly.
L3: OFF.
4 Turn SW2 ON (during engine 12 V L1: OFF. Charge light inspection.
operation). L2: ON. Power generation inspection.
L3: ON. Electrothermal choke actuation inspection.
5 Switch SW1 and SW2 ON, gradually 14.5 ± 0.6 V L1: OFF.
increase voltage from 12 V. L2: OFF. Regulated voltage inspection.
L3: ON.
6 Return voltage to 12 V. 12 V L3: ON
L2: ON.
L3: ON.

ALTERNATOR
No. Procedure Voltage Indicator Remarks
Additional Functions
7 Perform operation 5 and gradually 16.5 ± 1.0 V L1: ON. Excessive Voltage Warning.
increase voltage with SW1 and SW2 L2: OFF.
ON and SW3 OFF.
L3: OFF.
8 With SW1 and SW2 ON, turn SW3 10 V or less L1: ON. Low voltage warning.
on and gradually decrease voltage L2: ON.
from 12 V.
L3: ON.
9 Return voltage to 12 V and 12 V L1: ON. Terminal S disconnection warning.
disconnect terminal S. L2: ON.
L3: OFF.
10 Test the diode (refer to Diode on
page 11-19).

ALTERNATOR
Diode Brush
Check for continuity between terminals B and F Measure the length of the brush protruding from the
using a multimeter (Figure 11-18, (1)). brush holder (Figure 11-19).
1. Disconnect the diode wiring between terminals
B and F.
2. Set the multimeter in the XΩ range and
measure continuity between terminals B and F.
The multimeter should indicate continuity.
3. Switch the polarity between terminals B and F
and measure continuity again.
The multimeter should not indicate continuity.
Note: Measure in the diode measurement 0001765
range on an analog or digital multimeter.

If the multimeter does not indicate continuity or Figure 11-19
indicates continuity in both directions, replace the
diode. Standard Value 0.41 in (10.5 mm)
Replacement 0.33 in (8.4 mm)
Standard
(1)
(2) 0001764
Figure 11-18
Item Description
1 Multimeter
2 Diode Inspection

ALTERNATOR
Assembly of Brush Holder (1)
Note: Some types of brush holders do not have
a cover.
1. Insert the brush holder (Figure 11-20, (4)) tab (2)
(Figure 11-20, (1)) into the groove
(Figure 11-20, (2)) in the holder cover
(Figure 11-20, (3)).
(1) (2)
(3)
(3)
(4) 0001768
Figure 11-22
3. Maintain a gap of 0.047 in (1.2 mm) or more as
shown (Figure 11-22, (2)).
(4) 0001766 4. Tighten the interior bolt (Figure 11-22, (3)).
5. Make sure that the housing fits into the groove
Figure 11-20 (Figure 11-23, (2)) on the reverse side of the
brush holder cover (Figure 11-23, (1)).
Note: Figure 11-21 shows a brush holder
installed incorrectly. The tab is detached
from the groove (Figure 11-21, (1))
(1)
0001767 (1)
0001770
(2)
Figure 11-21
Figure 11-23
Note: The brush holder must be assembled
before the IC Regulator is assembled to
the alternator. CAUTION
If the housing is incorrectly assembled
2. Install the brush holder (Figure 11-22, (1)) to to the brush holder cover, the brush
the IC Regulator (Figure 11-22, (4)).
holder cover can pinch the rotor shaft
which can result in an unsatisfactory
seal.

ALTERNATOR
6. Make sure that the holder cover groove and the Tightening Torque
brush holder tab are aligned
Target Minimum Maximum
(Figure 11-24, (1)). Value Value Value
SI Unit 1.96 N•m 1.57 N•m 2.35 N•m
(2) Display
(1)
Conventional 19.9 16.0 23.9
Unit Display kgf•cm kgf•cm kgf•cm
0001769
Figure 11-24
7. Make sure that the inner part of the holder (1)
cover is not pinched (Figure 11-24, (2)).
Note: Figure 11-25 shows a brush holder
cover installed incorrectly. The brush (2) 0001772
holder tab is detached from the holder

Figure 11-26
cover groove (Figure 11-25, (1)) and the
inner part of the holder cover is pinched
(Figure 11-25, (2)).
(1) (2)
0001771
Figure 11-25
8. Make sure that the two brushes contact the slip
rings on the rotor shaft.
9. Press as shown (Figure 11-26, (2)) and secure
with the two bolts (Figure 11-26, (1)).

ALTERNATOR
Assembly of Alternator
1. If removed, install the thrust washer
(Figure 11-27, (2)) in the rear frame housing.
Lubricate the outside diameter of a new bearing
(Figure 11-27, (1)). Press the bearing into the
rear frame housing.
(3)
(1)
(2)
0001677A
FIgure 11-29
(2)
(1) 5. Align the front frame housing with the rear
0001679A
frame housing. Install the four bolts
Figure 11-27 (Figure 11-30, (1)) and four nuts
(Figure 11-30, (2)).
2. If removed, lubricate the outside diameter of a
new front frame housing bearing. Press the
bearing (Figure 11-28, (2)) into the front frame
housing. Install the plate (Figure 11-28, (4)) to (2)
the front housing. Tighten the four bolts
(Figure 11-28, (3)).
(1)
(4)
0001676A
(3) Figure 11-30
(2) 6. Install the insulation bushing

(FIgure 11-31, (4)) and nuts
(FIgure 11-31, (3)).
(1)
(3)
(4)
0001678A
Figure 11-28
3. Position the stator assembly (Figure 11-28, (1))
on the front frame housing studs.
(1)
4. Lubricate the shaft of the rotor assembly
(2)
(FIgure 11-29, (1)). Press the rotor assembly
into the front frame housing (FIgure 11-29, (2))
and rear frame housing (FIgure 11-29, (3)). 0001675A
FIgure 11-31
CAUTION
Be careful not to drop the rotor. Damage
to the slip rings or fan can result.

ALTERNATOR
7. Install the rear cover (Figure 11-32, (2)) to the Installation of Alternator
rear frame housing with three bolts
(Figure 11-32, (1)). 1. Position the alternator on the gearcase. Loosely
install the nut (FIgure 11-34, (2)) on the
gearcase stud and the V-belt adjuster bolt
(FIgure 11-34, (1)).
(3)
(1)
(1)
(4) (2)
(5)
0001674A
Figure 11-32
(2) (3)
8. Assemble the pulley (Figure 11-33, (2)) and nut
(Figure 11-33, (1)) to the shaft of the rotor
assembly. Tighten the nut. 0001672A
FIgure 11-34
2. Connect the electrical wires to the alternator.
Tighten the nuts to 15 - 20 in lbs (1.7-2.3 N•m,
(2) 17-23 kgf•cm)
(1) 3. Install the V-belt. Tighten the V-belt to the
Fan V-belt on page 5-22.
0001673A 4. Start the engine. Listen for any unusual sounds
Figure 11-33 from the alternator.
CAUTION
0000049en
5. Verify that the charge indicator is ON while the

engine is operating. If the charge indicator is
not ON, repair the problem before operating the
engine.

ALTERNATOR
Bench Test
(1)
1. Check that the test bench is set up and that the (9) (2)
charge light is ON.
(3)
2. Position the alternator (Figure 11-35, (1)) in the
test bench.
(6) (4)
3. Insert the main wiring harness (8)
(Figure 11-35, (6)) inspection connector into (5)
the alternator (Figure 11-35, (1)). (7)
0001776
4. Connect the main wiring harness
(Figure 11-35, (6)) and sub-wiring harness C Figure 11-35
(Figure 11-35, (7)).
Item Description
5. Connect the voltmeter (Figure 11-35, (2) and
(3)) and the ammeter (Figure 11-35, (5)) as 1 Alternator
shown. 2 Voltmeter Positive Side (+)
6. Turn SW1 ON and check that the main wiring 3 Voltmeter Negative Side (-)
harness light (the charge light) 4 To Battery Negative (-) Terminal
(Figure 11-35, (8)) turns ON.
5 To Ammeter Positive (+) Terminal
Note: If terminal S is disconnected during
inspection, the charge light 6 Main Wiring Harness
(Figure 11-35, (8)) may remain ON 7 Sub-wiring Harness C
continuously. In this case, use sub-wiring 8 Light
harness B instead of sub-wiring harness
C. Connect terminal S of sub-wiring 9 Terminal B
harness B to terminal S on the alternator,
turn SW1 ON, connect IG and L and
check again.
7. Turn the test bench motor ON, increase speed
and check that the charge light turns OFF
(Figure 11-35, (8)).

ALTERNATOR
Test Wiring
Wiring Diagram for Alternators with an M Type Regulator.
0001777
Wiring Diagram for Alternators with a GS Type Regulator.
0001778
Wiring Diagram for Alternators with a D or GA Type Regulator.
0001779
Wiring Diagram for Alternators with a GL Type Regulator.
0001780

ALTERNATOR
Regulated Voltage Check 3. While adjusting the speed and load resistance,
1. Turn battery switch S1 ON. set the speed and the voltage to the standard
values.
2. Run the alternator. Turn the load switch S2 ON
when output current exceeds 0 (A). 4. Check that the current is within the standard
values.
3. Adjust the speed and the load to the standard
values.
4. Check that the voltage is within the standard
values.
Note: Regulated voltage has the temperature
characteristics shown in (Figure 11-36).
Perform the measurement quickly.
0001781
Figure 11-36
No Load Test
1. Turn battery switch S1 ON.
2. Run the alternator. Turn S1 OFF when output
current exceeds 0 (A).
3. Adjust the speed and the voltage to the
standard values.
4. Check that the speed is within the standard
values.
Output Test
1. Turn battery switch S1 ON and load switch S2
ON.
2. Run the alternator.

Section 12
ELECTRIC WIRING
TNE Service Manual
Table of Contents
Page
Electric Wiring Precautions ........................................................... 12-3
Electrical Wire Resistance............................................................. 12-4
Battery Cable Resistance.............................................................. 12-5
Electrical Wire Sizes - Voltage Drop ............................................. 12-6
Conversion of AWG to European Standards................................. 12-7
Electric Wiring Diagram................................................................. 12-8

ELECTRIC WIRING

ELECTRIC WIRING
ELECTRIC WIRING CAUTION

PRECAUTIONS Removing the battery cables or battery
Failure to follow these precautions may result in the while the engine is operating may cause
failure of an electrical component and the loss of damage to the current limiter depending
warranty coverage on that item as well as related on the electrical equipment being used.
items. Make sure that all users read and This situation could cause loss of
understand these precautions. control of output voltage. The
continuous high voltage of 23-24 volts
(for 5000 rpm dynamo) will damage the
CAUTION current limiter and other electrical
Do not reverse the positive and negative equipment.
ends of the battery cable. The alternator 0000058en
0000050en
CAUTION
Reversing the battery cable connections
CAUTION at the battery or on the engine will
When the battery indicator goes out, it destroy the SCR diode in the current
should not come on again. The battery limiter. This will cause the charging
indicator only comes on during system to malfunction and may cause
operation if the alternator fails or if the damage to the electrical harnesses.
V-belt breaks. However, if an LED is 0000059en
operation.
0000051en
CAUTION
Make sure that the combined total
resistance of the battery cable in both
directions between the starter motor
and the battery is within the value
indicated in the Battery Cable
Resistance chart in the Electric Wiring
Section of this manual. The starter
motor will malfunction and fail if the
resistance is higher than the specified
value.
0000057en

ELECTRIC WIRING
ELECTRICAL WIRE RESISTANCE

Metric Ohms / Foot
AWG
Nominal mm² Resistance
20 0.5 0.009967
18 0.8 0.006340
16 1.25 0.004359
14 2 0.002685
12 3 0.001704
10 5 0.001073
8 8 0.000707
6 15 0.000421
4 20 0.000270
2 30 0.000158
1 40 0.000130
0 (1/0) 50 0.000103
00 (2/0) 60 0.000087
000 (3/0) 85 0.000066
0000 (4/0) 100 0.000051
Wiring voltage drop should not exceed 5% [0.05] x 12 Volts = 0.6 Volts.
Voltage Drop = Current [Amps] x Length of Wire [Feet] x Resistance per Foot [Ohms]
Example:
Current draw of 100 Amps x 3 feet of 4 AWG wire
100 Amps x 3 Feet x 0.000270 = 0.08 Volts [Voltage Drop]

ELECTRIC WIRING
BATTERY CABLE RESISTANCE

Maximum Total Battery Cable Length
(Positive Cable + Negative Cable + a*)
AWG mm² 12V Starter Motor Output
Less Than 2.68 HP (2 kW) Greater Than 2.68 HP (2 kW)
m ft. m ft.
6 15 1.5 4.75 N/A N/A
4 20 2.3 7.4 N/A N/A
2 30 3.8 12.6 2.3 7.5
1 40 4.6 15.3 2.8 9.2
0 (1/0) 50 5.9 19.5 3.5 11.6
00 (2/0) 60 7.0 22.8 4.2 13.7
000(3/0) 85 9.3 30.5 5.6 18.3
0000 (4/0) 100 11.9 39.0 7.1 23.4
00000 (5/0) 125 N/A N/A 8.3 27.3
000000 (6/0) 150 N/A N/A 10.1 33.3
Note: Total allowable resistance of the complete battery cable circuit (positive cable + negative cable + a*)
(a*: Resistance (Ω) of a battery switch or other electrical equipment having high resistance)
For starter motors of less than 2.68 HP (2 kW): the total resistance must be less than 0.002 Ω
For starter motors of greater than 2.68 HP (2 kW): the total resistance must be less than 0.0012 Ω

ELECTRIC WIRING
ELECTRICAL WIRE SIZES - VOLTAGE DROP

Total Length of conductor from source of current to device and back to source—feet
current on
circuit in 10 15 20 25 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170
amps.
12 Volts Wire Size (AWG)
5 18 16 14 12 12 10 10 10 8 8 8 6 6 6 6 6 6 6 6
10 14 12 10 10 10 8 6 6 6 6 4 4 4 4 2 2 2 2 2
15 12 10 10 8 8 6 6 6 4 4 2 2 2 2 2 1 1 1 1
20 10 10 8 6 6 6 4 4 2 2 2 2 1 1 1 0 0 0 2/0
25 10 8 6 6 6 4 4 2 2 2 1 1 0 0 0 2/0 2/0 2/0 3/0
30 10 8 6 6 4 4 2 2 1 1 0 0 0 2/0 2/0 3/0 3/0 3/0 3/0
40 8 6 6 4 4 2 2 1 0 0 2/0 2/0 3/0 3/0 3/0 4/0 4/0 4/0 4/0
50 6 6 4 4 2 2 1 0 2/0 2/0 3/0 3/0 4/0 4/0 4/0
60 6 4 4 2 2 1 0 2/0 3/0 3/0 4/0 4/0 4/0
70 6 4 2 2 1 0 2/0 3/0 3/0 4/0 4/0
80 6 4 2 2 1 0 3/0 3/0 4/0 4/0
90 4 2 2 1 0 2/0 3/0 4/0 4/0
100 4 2 2 1 0 2/0 3/0 4/0
24 Volts
5 18 18 18 16 16 14 12 12 12 10 10 10 10 10 8 8 8 8 8
10 18 16 14 12 12 10 10 10 8 8 8 6 6 6 6 6 6 6 6
15 16 14 12 12 10 10 8 8 6 6 6 6 6 4 4 4 4 4 2
20 14 12 10 10 10 8 6 6 6 6 4 4 4 4 2 2 2 2 2
25 12 12 10 10 8 6 6 6 4 4 4 4 2 2 2 2 2 2 1
30 12 10 10 8 8 6 6 4 4 4 2 2 2 2 2 1 1 1 1
40 10 10 8 6 6 6 4 4 2 2 2 2 1 1 1 0 0 0 2/0
50 10 8 6 6 6 4 4 2 2 2 1 1 0 0 0 2/0 2/0 2/0 3/0
60 10 8 6 6 4 4 2 2 1 1 0 0 0 2/0 2/0 3/0 3/0 3/0 3/0
70 8 6 6 4 4 2 2 1 1 0 0 2/0 2/0 3/0 3/0 3/0 3/0 4/0 4/0
80 8 6 6 4 4 2 2 1 0 0 2/0 2/0 3/0 3/0 3/0 4/0 4/0 4/0 4/0
90 8 6 4 4 2 2 1 0 0 2/0 2/0 3/0 3/0 4/0 4/0 4/0 4/0 4/0
100 6 6 4 4 2 2 1 0 2/0 2/0 3/0 3/0 4/0 4/0 4/0

ELECTRIC WIRING
CONVERSION OF AWG TO EUROPEAN STANDARDS

Conductor Size Conductor Diameter Conductor Cross-sectional Area
(AWG) (mm) (mm2)
25 0.455 0.163
24 0.511 0.205
23 0.573 0.259
22 0.644 0.325
21 0.723 0.412
20 0.812 0.519
19 0.992 0.653
18 1.024 0.823
17 1.15 1.04
16 1.29 1.31
15 1.45 1.65
14 1.63 2.08
13 1.83 2.63
12 2.05 3.31
11 2.30 4.15
10 2.59 5.27
9 2.91 6.62
8 3.26 8.35
7 3.67 10.6
6 4.11 13.3
5 4.62 16.8
4 5.19 21.2
3 5.83 26.7
2 6.54 33.6
1 7.35 42.4
0 (1/0) 8.25 53.4
00 (2/0) 9.27 67.5
000(3/0) 10.40 85.0
0000 (4/0) 11.68 107.2
00000 (5/0) 13.12 135.1
000000 (6/0) 14.73 170.3
1.1 circular mil (CM) ≅ 0.0005067 mm 2

ELECTRIC WIRING
ELECTRIC WIRING DIAGRAM

Section 13
TROUBLESHOOTING
TNE Service Manual
Table of Contents
Page
Special Service Tools.................................................................... 13-3
Troubleshooting By Measuring Compression Pressure ................ 13-4
Quick Reference Table For Troubleshooting ................................ 13-6

TROUBLESHOOTING

TROUBLESHOOTING
SPECIAL SERVICE TOOLS

Compression Gauge Kit For measuring compression pressure
Gauge Set Code No. TOL-97190080
0000849

TROUBLESHOOTING
TROUBLESHOOTING BY 3. Crank the engine with the stop handle at the

stop position (no injection state) before
MEASURING COMPRESSION installing the compression gauge
PRESSURE (Figure 13-1, (1)) adapter.
Compression pressure drop is one of major causes 4. Install a gasket at the tip end of the
of increasing blow-by gas (engine oil contamination compression gauge adapter. Install the
or increased engine oil consumption as a resultant compression gauge and the compression
phenomenon) or starting failure. The compression gauge adapter at the cylinder to be measured.
pressure is affected by the following factors: 5. Crank the engine until the compression gauge
reading is stabilized.
1. Degree of clearance between piston and
cylinder
2. Degree of clearance at intake / exhaust valve
seat
3. Gas leak from nozzle gasket or cylinder head
gasket
The pressure will drop due to increased parts wear.
Pressure drop reduces the durability of the engine.
A pressure drop may also be caused by scratched
cylinder or piston by dust entrance from the dirty air
cleaner element or worn or broken piston ring.
Measure the compression pressure to determine
the condition of the engine.
0001621
Compression Pressure Measurement
Figure 13-1
Method
1. Warm up the engine. 6. After performing the compression check,
remove the compression gauge and
2. Stop the engine. Remove the high-pressure fuel compression gauge adapter from the cylinder.
injection lines as an assembly from the engine. Install the fuel injector and high-pressure fuel
Remove the fuel injector from the cylinder to be injection lines. See Installation of Fuel
measured. See Removal of the Fuel Injectors on page 7-39.
Injectors on page 7-35.
CAUTION
Remove the high-pressure fuel injection
lines as an assembly whenever
possible. Disassembling the
high-pressure fuel injection lines from
lines will make it difficult to reinstall the
fuel lines.
0000047en

TROUBLESHOOTING
Standard Compression Pressure
Engine compression pressure list (reference value)
Compression Pressure
Engine Model at 250 rpm (250 min-1) Deviation Between Cylinders
Standard Limit
4TNE92-NMH
426 ± 15 psi 341 ± 15 psi 29 to 43 psi
4TNE92-NMHA
(2.94 ± 0.1 MPa, 30 ± 1 kgf/cm²) (2.35 ± 0.1 MPa, 24 ± 1 kgf/cm²) (0.2 to 0.3 MPa, 2 to 3 kgf/cm²)
4TNE98-NMH
Engine Speed and Compression Pressure (Use for Reference)
2
MPa Kgf/cm
3.43 35
Standard
2.94 30
Limit
2.45 25
1.96 20
200 250 300 350 400

Cranking rpm 0001622
Figure 13-2

TROUBLESHOOTING
Measured Value and Troubleshooting
When the measured compression pressure is
below the limit value, inspect each part by referring
to the table below.
No. Item Cause Corrective Action

Clogged element Clean the element.
1 Air Cleaner Element Broken element
Replace the element.
Defect at element seal portion
2 Valve Clearance Excessive or no clearance Adjust the valve clearance.
3 Valve Timing Incorrect valve clearance Adjust the valve clearance.
Replace the gasket.
4 Cylinder Head Gasket Gas leak from gasket
Retighten the cylinder head bolts to the specified torque.
Intake/Exhaust Valve Sticking valve Replace the intake/exhaust valve.
5 Gas leak due to worn valve seat
Valve Seat Lap the valve seat.
or foreign matter trapped in valve
Piston
Gas leak due to scratching or
6 Piston Ring Perform honing and use an oversized part.
wear
Cylinder
QUICK REFERENCE TABLE

FOR TROUBLESHOOTING
The following table summarizes the general trouble
symptoms and their causes. If any trouble symptom
occurs, take corrective action before it becomes a
serious problem so as not to shorten the engine
service life.

Trouble Symptom Insufficient Poor
Starting Problem Engine Exhaust Engine Engine Oil Engine Air
Surging Coolant Intake
Output Color
Engine Starts
Exhaust During
But Stops Color Work
Soon.
Exhaust
Smoke
Corrective Action
Cause
Engine Does Not Start.

None
Little
Much
Ordinary
White
Black
White
Black
High Knocking Sound During Combustion
Abnormal Engine Sound
Uneven Combustion Sound
During Idling
During Work Operation
Excessive Engine Vibration
Difficulty in Returning to Low Speed
Excessive Fuel Consumption
Excessive Oil Consumption
Dilution by Diesel Fuel
Oil with Water
Low Oil Pressure
Excessive Blow-by Gas
Overheat
Low Water Temperature
Pressure Drop
Pressure Rise
Exhaust Temperature Rise
TNE Service Manual

Improper Intake/Exhaust Valve Adjust the Valve Clearance.
O O O O O O
Clearance (See page 6-32)
Compression Leakage from Lap the Valve Seat.
Valve Seat O O O O O O O O (See page 6-27)
Intake/Exhaust Valve Seizure Correct or Replace
O O O O O O O O O O O Intake/Exhaust Valve.
(See page 6-29 and 6-26)
Cylinder Head Gasket Blowout O O O Replace the Gasket.
(See page 6-30)
Seized or Broken Piston Ring Replace the Piston Ring.
O O O O O O O O O O O O
(See page 6-49)
Worn Piston Ring, Piston or Perform Honing and Use
Cylinder O O O O O O O Oversize Parts.
(See page 6-48)
Seized Crankpin Metal or Repair or Replace.
Bearing O O O O O O O (See page 6-50)

Improper Arrangement of Correct the Ring Joint
Piston Ring Joints O O O O Positions.
(See page 6-49)
Reverse Assembly of Piston O O O O Reassemble Correctly.
Engine System
Rings (See page 6-49)
Worn Crankpin and Journal Measure and Replace.
O O O O O O
Bearing (See page 6-45)
Loose Connecting Rod Bolt Tighten to the Specified
O O O Torque.
(See page 6-12)
Foreign Matter Trapped in Disassemble and Repair.
Combustion Chamber O O O O (See page 6-21)
Excessive Gear Backlash O Adjust Gear Meshing.
(See page 6-8)
Worn Intake/Exhaust Valve Measure and Replace.
O O O
Guide (See page 6-26 and 6-28)
Governor Adjusted Incorrectly Make Adjustment.
O O O O O (See page 5-28)
Improper Open/Close Timing O O O O O O Adjust the Valve Clearance.
of Intake/Exhaust Valves (See page 5-29)
TROUBLESHOOTING
13-7
13-8
Trouble Symptom Insufficient Poor Engine Engine Air
Starting Problem Engine Exhaust Engine Oil
Output Color Surging Coolant Intake
Engine
Starts Exhaust During
but Stops Color Work
Soon.
Exhaust Corrective Action
Smoke
TROUBLESHOOTING
Cause

None
Little
Much
Ordinary
White
Black
White
Black
During Idling
Oil with Water
Low Oil Pressure
Overheat
Pressure Drop
Pressure Rise
Replace Thermostat.
Excessive Radiator Cooling O O O (See page 8-12)
Replace Thermostat or Check
Insufficient Radiator Cooling O O O for Loose Fan Belt.
(See page 5-22 and 8-12)
Check Water Leakage from
Insufficient Engine Coolant Level O O O Engine Coolant System.
(See page 8-11)
Cracked Water Jacket O O O Repair or Replace.
(See page 8-12)
Adjust the Belt Tension.
Engine Coolant System

Stretched Fan Belt O O O
(See page 5-22)
Check or Replace.
Defective Thermostat O O O O (See page 8-12)
Incorrect Engine Oil O O O O O O Use Correct Engine Oil.
(See page 4-14)
Engine Oil System Leakage O O Repair.
Insufficient Delivery Capacity of O Check and Repair.
Trochoid Pump (See page 9-7)
Clean or Replace.
Clogged Engine Oil Filter O O
(See page 5-26)
Defective Pressure Regulating
O Clean, Adjust or Replace.
Engine Oil System

Valve
Add Correct Engine Oil.
Insufficient Engine Oil Level O O (See page 4-15)
Too Early Timing of Fuel Injection O O O O Check and Adjust.
Pump (See page 7-33)
Too Late Timing of Fuel Injection Check and Adjust.
O O O O O O
TNE Service Manual

Pump (See page 7-33)
Use Correct Diesel Fuel.
Incorrect Diesel Fuel O O O O O O (See page 4-9)
Water in Fuel System O O O O O O O Drain the Fuel Filter.
(See page 5-19)
Fuel System
Clean or Replace.
Clogged Fuel Filter O O O
(See page 5-31)
Bleed the Air.
Air in Fuel System O O O (See page 4-12)
Trouble Symptom Poor
Insufficient Engine Engine Air
Starting Problem Engine Output Exhaust Surging Engine Oil Coolant Intake
Color
Engine Starts
Exhaust During
but Stops Color Work
Soon.
Exhaust
Smoke Corrective Action
Cause

None
Little
Much
Ordinary
White
Black
White
Black
During Idling
Oil with Water
Low Oil Pressure
Overheat
Pressure Drop
Pressure Rise
Clogged or Cracked Fuel O O O Clean or Replace.

Line (See page 5-36)
Check the Fuel Tank
TNE Service Manual

Insufficient Fuel Supply to Cock, Fuel Filter, Fuel
Fuel Injection Pump O O O Line, and Fuel Feed
Pump.
Uneven Injection Volume Check and Adjust.
from Fuel Injection Pump O O O O O O O O O (See page 7-36)
Excessive Fuel Injection O O O O O O O Check and Adjust.
Volume (See page 7-36)
Poor Spray Pattern from Check and Adjust.
O O O O O O O O O
Fuel Injection Nozzle (See page 7-36)
Fuel System
Foreign Matter
Trapped in the Valve
Priming Failure O Inside the Priming
Pump (Disassemble
and Clean).
(See page 7-28)
Clogged Strainer at Feed

Pump Inlet O Clean the Strainer.
Clogged Air Filter O O O O O Clean Air Filter.

(See page 5-34)
Engine Used at High
Study Output Drop
Temperatures or at High O O O O O and Load Matching.
Altitude
Clogged Exhaust Pipe O O O O Clean Exhaust Pipe.
Air/Exhaust Gas System

Repair or Replace
Starting Motor Defect O Stater Motor.
(See page 10-10)
Repair or Replace
Alternator Defect O Alternator.
(See page 11-12)
Open-Circuit in Wiring O Repair Open Circuit.
Electrical System
Inspect and Change
Battery Voltage Drop O the Battery.
(See page 5-23)
TROUBLESHOOTING
13-9
TROUBLESHOOTING

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TNE Service Manual

English Language Manual Available

ii TNE Service Manual

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iv TNE Service Manual

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1-2 TNE Service Manual

TNE Service Manual 2-1

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2-2 TNE Service Manual

YANMAR LIMITED WARRANTY

How Long is the Warranty Period?

What the Engine Owner Must Do:

To Locate an Authorized Yanmar Industrial Engine Dealer or Distributor:

What Yanmar Will Do:

TNE Service Manual 2-3

What is Not Covered by this Warranty?

2-4 TNE Service Manual

YANMAR CO., LTD. LIMITED EMISSION CONTROL SYSTEM

Manufacturer’s Warranty Period:

Engine Type Warranty Period by Number of Years or Hours of Operation

TNE Service Manual 2-5

2-6 TNE Service Manual

Exclusions: Owner’s Warranty Responsibilities:

TNE Service Manual 2-7

This Page Intentionally Left Blank

2-8 TNE Service Manual

situation which, if not avoided, will

TNE Service Manual 3-1

SAFETY PRECAUTIONS During Operation and Maintenance

Before You Operate A DANGER

3-2 TNE Service Manual

FIRE AND EXPLOSION HAZARD! FIRE AND EXPLOSION HAZARD!

FIRE AND EXPLOSION HAZARD!

TNE Service Manual 3-3

FIRE AND EXPLOSION HAZARD! FIRE AND EXPLOSION HAZARD!

is under pressure and fuel could spray

3-4 TNE Service Manual

FIRE AND EXPLOSION HAZARD!

TNE Service Manual 3-5

SEVER HAZARD! EXHAUST HAZARD!

3-6 TNE Service Manual

TNE Service Manual 3-7

3-8 TNE Service Manual

TNE Service Manual 3-9

3-10 TNE Service Manual

TNE Service Manual 3-11

3 minutes) at an angle greater than 25°

3-12 TNE Service Manual

engine’s safety and performance

TNE Service Manual 3-13

3-14 TNE Service Manual

TNE Service Manual 4-1

4-2 TNE Service Manual

COMPONENT IDENTIFICATION LOCATION OF LABELS