gn125f PDF

GN125F
99500H3030DE001
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FOREWORD GROUP INDEX
This manual contains an introductory description on the
SUZUKI GN125F and procedures for its inspec-
tion/service and overhaul of its main components. Other
information considered as generally known is not
GENERAL INFORMATION 1
included.
2
Read the GENERAL INFORMATION section to familia-
rize yourself with the motorcycle and its maintenance.
PERIODIC MAINTENANCE
Use this section as well as other sections to use as a
guide for proper inspection and service.
This manual will help you know the motorcycle better so
3
that you can assure your customers of fast and reliable
service. ENGINE
* This manual has been prepared on the basis of the 8
latest specifications at the time of publication. If
modifications have been made since then, differ-
ences may exist between the content of this manual
and the actual motorcycle.
FUEL AND LUBRICATION 4
* Illustrations in this manual are used to show the
5
basic principles of operation and work procedures.
They may not represent the actual motorcycle CHASSIS
exactly in detail.
* This manual is written for persons who have enough
knowledge, skills and tools, including special tools,
6
for servicing SUZUKI motorcycles. If you do not
have the proper knowledge and tools, ask your ELECTRICAL
authorized SUZUKI motorcycle dealer to help you.
7
WARNING
SERVICING INFORMATION
Improper repair may result in injury to the
mechanic and may render the motorcycle unsafe
for the rider and passenger.
CAUTION
Inexperienced mechanics or mechanics without

proper tools, not to able to properly perform the
services described in this manual.
DACHANGJIANG GROUP CO.,LTD.

DECEMBER, 2014
(The 1st Edition)
©COPYRIGHT DA CHANGJIANG GROUP CO.,LTD. 2014

HOW TO USE THIS MANUAL
TO LOCATE WHAT YOU ARE LOOKING FOR:
1.The text of this manual is divided into 7 sections.
2.The section titles are listed in the GROUP INDEX.
3.Holding the manual as shown as at the right will allow you to find
the first page of the section easily.
4.The contents are listed on the first page of each section to help
you find the item and page you need.
COMPONENT PARTS AND WORK TO BE DONE

Under the name of each system or unit, is its exploded view. Work instruction and tightening torque,
lubricating points and locking points, are provided.
Example: Front wheel
1 Front axle shaft

2 Spacer
3 Dustcover
4 Washer
5 Front brake disc
6 Oil seal
7 Roller bearing
8 Spacer
9 Front tire
10 Front wheel rim
11 Speedometer gear driver
12 Oil seal
13 Speedometer gear box
A Brake disc bolt
B Front axle nut
ITEM N•m Kgf•m
A 18-28 1.8-2.8
B 36-52 3.6-5.2

SYMBOL
The following symbols are instructions and necessary information for maintenance.
SYMBOL DEFINITION SYMBOL DEFINITION
Torque control required.

Apply THREAD LOCK “1360"
Data beside it indicates specified
99000-32130
torque.
Apply oil. Use engine oil unless

OIL
Apply or use the absorber oil

otherwise specified.
Apply SUPER GREASE “A”

Apply or use the brake fluid
99000-25010
Apply MOLY PASTE

Measure voltage
99000-25140
Apply sealant “1215”

Measure in resistance
99000-31110
Apply sealant “1207B”

Measure continuity test range
99000-31140

Use special tool
99000-32050

The data of maintenance
99000-32030

WIRE COLOR
B ............. Black Gr ............. Grown R ............. Red
Bl ............. Blue Lbl............. Light blue V ............. Violet
Br ............. Brown Lg ............. Light green W ............. White
Dg ............. Deep green O ............. Orange Y ............. Yellow
G ............. Green P ............. Pink
B/Bl ............. Black with Blue tracer O/Bl ............. Orange with Blue tracer
B/Br ............. Black with Brown tracer O/W ............. Orange with White tracer
B/G ............. Black with Green tracer O/Y ............. Orange with Yellow tracer
B/R ............. Black with Red tracer R/B ............. Red with Black tracer
B/W ............. Black with White tracer R/Y ............. Red with Yellow tracer
B/Y ............. Black with Yellow tracer W/B ............. White with Black tracer
Bl/W ............. Blue with White tracer W/R ............. White with Red tracer
Bl/Y ............. Black with Yellow tracer Y/G ............. Yellow with Green tracer
Br/Y ............. Brown with Yellow tracer Y/R ............. Yellow with Red tracer
G/Y ............. Green with Yellow tracer Y/W ............. Yellow with White tracer
O/B ............. Orange with Black tracer

GENERAL INFORMATION
1
1
CONTENTS
WARNING/CAUTION/NOTE 1-1
GENERAL PRECAUTIONS 1-1
SERIAL NUMBER LOCATION 1-2
FUEL AND OIL RECOMMENDATION 1-2
BREAK-IN PROCEDURE 1-2
SPECIFICATIONS 1-3

GENERAL INFORMATION
WARNING/CAUTION/NOTE
Please read this manual and follow its instructions carefully. To emphasize special information, the
symbol and the words WARNING,CAUTION and NOTE have special meanings. Pay special attention to
the messages highlighted by these signal words.
WARNING
Indicates a potential hazard that could result in death or injury.
Indicates a potential hazard that could result in motorcycle damage.
NOTE:
Indicates special information to make maintenance easier or instructions clearer.
Please note, however, that the warnings and the cautions contained in this manual cannot possibly cover
all potential hazards relating to the servicing, or lack of servicing of the motorcycle. In addition to the
WARNING and CAUTION stated, you must use good judgment and basic mechanical safety principles. If
you are unsure about how to perform a particular service operation, ask a more experienced technician for
advice.
GENERAL PRECAUTION
WARNING
Proper service and repair procedures are important for the safety of the service technician and the
safety and reliability of the motorcycle.
When 2 or more persons work together, pay attention to safety of each other.
When it is necessary to run the engine indoors, make sure that exhaust gas is forced outdoor.
When working with the toxic or flammable materials, make sure that the area you work in is well-
ventilated and that you follow all of the material manufacturer's instructions.
Never use gasoline as a cleaning solvent.
To avoid getting burned, do not touch the engine, engine oil or exhaust system during or for a while
after engine operation.
After servicing fuel, oil, exhaust or brake system, check all lines and fittings related to the system
for leakage.
1-1

GENERAL INFORMATION
If parts replacement is necessary, replace the parts with SUZUKI GENUINE PARTS or their
equivalent.
When removing parts that are to be reused, keep them arranged in an orderly manner so that they
may be reinstalled in the proper order and orientation.
Be sure to use special tools when instructed.
Make sure that all parts used in reassembly are clean, and also lubricated when specified.
When use of a certain type of lubricant, bond, or sealant is specified, be sure to use the specified
type.
When performing service to electrical parts, if the service procedures not require used of battery
power, disconnect the positive terminal.
When removing the battery, disconnect the negative cable first and then the positive cable.
When reconnecting the battery, connect the positive cable first and then the negative cable, and
replace the terminal cover on the positive terminal.
Tighten cylinder head and case bolts and nuts, beginning with larger diameter and ending with
smaller diameter, from inside to outside diagonally, to the specified tightening torque.
Whenever you remove oil seals, gaskets, packing, O-rings, locking washers, cotter pins, cir-clips,
and certain other parts as specified, be sure to replace them with new ones. Also, before installing
these new parts, be sure to remove any odd material from the mating surfaces.
Never reuse a circlip. When installing a new circlip, take care not to expend the end gap larger than
required to slip the circlip over the shaft. After installing a circlip, always ensure that it is completely
seated in its groove and securely fitted.
Do not use self-locking nuts a few times over.
Use a torque wrench to tighten fasteners to the torque values when specified. Wipe off grease or oil
if a thread is smeared with them.
After reassembly, check parts for tightness and operation.
NOTE:
* To protect environment, do not unlawfully dispose of used motor oil and other fluids,
batteries and tires.
* To protect earth's natural resources, properly dispose of used motorcycles and parts.
1-2

GENERAL INFORMATION
SERIAL NUMBER LOCATIONS

The frame serial number or V.I.N. (Vehicle BRAKE FLUID
Identification Number) 1 is stamped on the right
DOT4
side of the steering head pipe. The engine serial
number 2 is located on the left side of the ABSORBER OIL
crankcase. These numbers are required
especially for registering the machine and SUZUKI ABSORBER OIL #32 OR EQUIVALENT
ordering spare parts.
BREAK-IN PROCEDURE
During the manufacture only the best p ossible
materials are used and all machined parts are
finished to a very high standard , it is still necessary
to allow the moving part to “BREAK-IN” before
subjecting the engine to maximum stresses . The
future performance and reliability of the engine
FUEL AND OIL depend s on the care and restraint exercised during
its early life . The general rules are as follows:
RECOMMENDATIONS
The throttle must not be opened to the full during
FUEL
the new motorcycle's break-in period. Throttle
Use fuel with an octane number of 90-97 opening should be limited to less than 3/4 of its
(Research method), preferably unleaded. maximum, while violent acceleration should be
avoided.
NOTE: Do not maintain constant engine gear and
Unleaded fuel will extend spark plug life. speed for an extended time period during any
portion of the break-in. Try to vary the throttle
ENGINE OIL position. During the period of break-in, increase
Be sure that the motorcycle engine oil you use the throttle opening properly to enable break-in
comes under API classification of SF or SG and its fully.
viscosity rating is SAE 10W-40. If SAE 10W-40 When engine is running at constant low speed
engine oil is not available, select the oil viscosity (low load), parts will wear rapidly leads to bad
according to the following chart: brake-in.
SAE
40
30
20W/50
10W/50
10W/30
20W
10W
C -20 -10 0 10 20 30 40
Temp.
F -4 14 32 50 68 86 104
1-2

GENERAL INFORMATION
SPECIFICATIONS
DIMENSIONS AND CURB WEIGHT
Overall length 2 000 mm
Overall width 815 mm
Overall height 1 100 mm
Wheelbase 1 300 mm
Ground clearance 175 mm
Curb weight 113 kg
ENGINE
Type Single cylinder, vertical, air-cooled, four stroke
Number of cylinders 1
Bore 57 mm
Stroke 48.8 mm
Piston displacement 124 ml
Compression ratio 9.2 : 1
Carburetor BS type
Air cleaner P olyurethane foam element
Starter system Electric
Lubrication system Wet sump
TRANSMISSION
Clutch Wet multi-plate type
Transmission 5-speed constant mesh
Primary reduction ratio 3.470
Final reduction ratio 2.867
Gear ratios, Low 3.000
2nd 1.857
3rd 1.368
4th 1.143
Top 0.957
Drive chain KMC 428H 116 links
1-3

GENERAL INFORMATION
ELECTRIC
Ignition type CDI
Ignition timing 13° B.T.D.C below 2 000 r/min
Spark plug NGK CR8E
Battery 12V 7Ah
Fuse 15 A
Headlight 12V, 35W/35W
Tail light/brake light 12V, 5W/21W
Turn signal light 12V, 10W
Position light 12V, 5W
CHASSIS
Front absorber Telescopic , coil spring, oil damped
Rear absorber Swingarm type, 5 level adjustable coil spring oil damped
Steering angle 42°
Caster 27 ° 50'
Trail 105 mm
Turning diameter 4 200 mm
Front brake Disc brake
Rear brake Drum brake
Front tire size 2.75-18 4PR
Rear tire size 3.50-16 4PR
Front absorber stroke 130 mm
CAPACITIES
Fuel tank 10 L
Reserve 2L
Engine oil, oil change 850 ml
with filter change 950 ml
Overhaul 1 300 ml
Front absorber oil (single) 168 ml
*The specifications subject to change without notice.
1-4

CONTENTS
PERIODIC MAINTENANCE 2-1
MAINTENANCE PROCEDURES 2-3 2
BATTERY/FUSE 2-3
AIR FILTER 2-4
MUFFLER NUT AND BOLT 2-5
CYLINDER HEAD, CYLINDER BOLTS AND NUTS 2-5
VALVE CLEARANCE 2-5
SPARK PLUG 2-6
ENGINE OIL 2-7
ENGINE OIL FILTER 2-7
OIL SUMP FILTER 2-8
CLUTCH CABLE PLAY 2-8
CARBURETOR(IDLING) 2-8
THROTTLE CABLE PLAY 2-9
FUEL HOSE 2-9
FUEL STRAINER 2-9
DRIVE CHAIN 2-10
BRAKES 2-11
TIRES 2-14
STEERING 2-14
FRONT AND REAR ABSORBER 2-14
LIGHTING AND SIGNAL 2-15
CHASSIS AND ENGINE MOUNTING BOLTS AND NUTS 2-15
COMPRESSION PRESSURE INSPECTION 2-17
OIL PRESSURE INSPECTION 2-18

The chart below lists recommended intervals for all the required periodic service work necessary to keep
the motorcycle operating at peak performance and economy. Mileages are expressed in terms of kilometer
and time for your convenience.
NOTE:
More frequent servicing may be performed on motorcycles that are used under severe conditions.
PERIODIC MAINTENANCE CHART

Interval Km Initial1 000 Every 5 000 Every 10 000
PAGE
Item Month 3 6 12
Battery / Fuse Inspect Inspect 2-3
Air cleaner Clean every 3 000 km 2-4
Muffler bolts Tighten Tighten 2-5
Cylinder head and cylinder nuts Tighten Tighten 2-5
Valve clearance (when cold) Inspect Inspect 2-5
Inspect Inspect
Spark plug 2-6
Replace every 10 000 km
Engine oil Change Change 2-7
Engine oil filter Replace Replace 2-7
Oil sump filter Clean 2-8
Clutch Inspect Inspect 2-8
Carburetor Inspect Inspect 2-8
Throttle cable clearance Inspect 2-9
Inspect Inspect
Fuel hose 2-9
Replace every 4 years
Fuel strainer Inspect Inspect 2-9
Drive chain Inspect, clean and lubricate every 1 000 km 2-10
Brakes Inspect Inspect
Inspect Inspect
Brakes Brake fluid hose 2-11
Replace every 4 years
Brake fluid Change every 2 years.
Tire Inspect Inspect 2-14
Steering Inspect Inspect 2-14
Front and rear absorber Inspect 2-14
Lighting and signal Inspect Inspect 2-15
Chassis bolts and nuts Inspect Inspect 2- 1 5
2-1

LUBRICATION CHART
Interval Km Initial and Every 5 000 Every 10 000

Item Month 6 12
Throttle cable Engine oil
Throttle grip Grease
Clutch cable Engine oil
Speedometer cable Grease
Speedometer gear box Grease
Tachometer cable Grease
Drive chain Motor oil, every 1 000 km
Brake pedal Grease or motor oil
Brake cam shaft Grease
Steering
Grease every 2 years or 20 000 km.
Swing arm bearings
WARNING
Be careful not to apply too much grease to the brake cam shafts. If grease gets on the
linings, break slippage will result.
CAUTION
Lubricate exposed parts which are subject to rust, with either motor oil or grease whenever the
motorcycle has been operated under wet or rainy conditions. Before lubricating each part, clean
off any rusty spots and wipe off any grease, oil dirt or grime.
2-2

MAINTENANCE PROCEDURES
This section describes the service procedures for each
section of Periodic Maintenance.
BATTERY / FUSE
Inspect Initial 1 000 km and every 5 000 km
BATTERY
The battery must be removed to check the electrolyte level
and specific gravity.
Remove the right frame cover.
Remove battery lead at the battery terminal.
Remove battery lead. 2
Remove battery from the chassis.
1
Check electrolyte for level and specific gravity. Add
distilled water, as necessary, to keep the surface of the
electrolyte above the LOWER level line 1 but not above the
UPPER level line 2 . For checking specific gravity, use a
hydrometer to determine the charged condition. An S.G.
O
reading of 1.28 (20 C) or under means that the battery
needs recharging off the machine: take it off and charge it
from a recharger. Charging the battery in place can lead to
failure of the regulator/rectifier.
O
Standard specific gravity: 1.28 ± 0.01 at 20 C
09900-28403 : Hydrometer
To install the battery, reverse the procedure described above.

CAUTION
When installing the battery lead wires, fix the lead first
and lead last.
Battery
Make sure that the breather pipe is tightly secured and

Breather pipe
undamaged, and is routed as shown in the figure.
FUSE
The fuse locates on the belt of the battery. In case of engine
stop suddenly or opened circuit, the fuse must be inspected.
WARNING
Do not use a fuse of a different specification , or it will
incur negative effect to electric, fire and power loss of
engine which is very dangerous.
Do not use aluminum, iron wire or any other substitute for
the fuse. If the fuse blows frequently, it indicates the
electric system may has problem. Always investigate the
cause, correct it and then replace the fuse.
2-3

AIR CLEANER
Clean every 3 000 km
If the air filter is clogged with dust, intake resistance will be

increased with a resultant decrease in output and an increase
in fuel consumption.
Check and clean the element in the following manner.
Remove the left frame cover.
Remove the screws and take off the air filter cover.
Separate the polyurethane foam element form the element

frame.
Fill a washing pan of a proper size with nonflammable clean- B

A
ing solvent. Immerse the element in the cleaning solvent and
wash it.
Non-flammable
Squeeze the cleaning solvent out of the washed element by Cleaning
Solvent
pressing it between the palms of both hands.
Immerse the element in motor oil, and squeeze the oil out of
the element leaving it slightly wet with oil.
CAUTION D C
Do not twist or wring the element because it will tear

or the individual cells of the element will be damaged. Motor oil
If driving under dusty condition , clean the air cleaner

element more frequently.
Reassemble the air cleaner in the reverse order of removal.
Remove the plug and drain water and oil at the periodic
maintenance interval.
CAUTION
Make sure the drain plug is fitted correctly after

cleaning .
If driving under humidity condition , clean the air
cleaner more frequently.
2-4

MUFFLER BOLTS
Inspect initial 1 000 km and tighten every 5 000 km
Tighten the muffler bolts 1 to the specified torque.
Muffler bolt 1 : 11~15 N•m
CYLINDER HEAD AND CYLINDER NUTS

Inspect initial 1 000 km and every 5 000 km.
Tighten four M10 nuts 1 to the specified torque when the

engine is cold.
Cylinder head nut: 21~25 N•m
Tighten the cylinder nut 2 and 3 to the specified torque.
Cylinder nut: 8-12 N • m
VALVE CLEARANCE
Inspect initial 1 000 km and every 5 000 km
Excessive valve clearance results in valve noise, insufficient

valve clearance results in valve damage and reduced power.
At the distances indicated above, check and adjust the valve
clearance to the following specification.
Remove the spark plug, valve timing inspection plug and
valve inspection caps .
Remove the generator cover cap and rotate the generator
rotor with wrench anticlockwise until the line on the rotor is
aligned with the center(arrow mark) of hole on the crankcase
to set the piston at TDC fo the compression stroke.
CAUTION
Valve clearance shoukld be checked when the engine is T
cold. Both the intake and exhaust valve must be

checked and adjusted when the piston is at TDC of the
compression stroke.
2-5

Hook the valve rocker arm with the special tool, insert the
thickness gauge to the valve stem end and the adjusting
screw on the rocker arm.
09900 - 20803 : Thickness gauge

11F14-017: Valve adjust spring
VALVE CLEARANCE SPECIFICATIONS
Valve clearance (when cold)
IN.: 0.04-0.07 mm EX.: 0.13-0.18 mm
If the clearance is off the specification, bring it into the

specified range by using the special tool.
SPARK PLUG
Inspect initial 1 000 km and every 5 000 km, replace
every 10 000 km.
Remove the carbon deposits with a wire of pin and adjust the
spark plug gap to 0.7-0.8 mm, measuring with a thickness
gauge.
When removing the carbon deposits, be sure to observe the
appearance of the plug, noting the color of the carbon
deposits. The color observed indicates whether the standard
plug is suitable or not. if the standard plug is apt to get wet, a
hotter plug should be used. If the standard plug is apt to
overheat (porcelain is whitish in appearance), replace with a
cooler one.
Spark plug gap: 0.7-0.8 mm

09900-20803: Thickness gauge 0.7-0.8 mm
TYPE NGK
Hot type CR7E
Standard CR8E
Cold type CR9E
2-6

ENGINE OIL
Change initial 1 000 km and every 3 000 km
Engine oil should be changed while the engine is hot.

Support the motorcycle by the center stand .
Drain the engine oil by removing the drain plug and filler cap
/ gauge.
Tighten the drain plug and pour new engine oil through the oil
filler. The engine will hold about 1 000 ml of oil. Use of SF/SG
in API with an oil viscosity of SAW 10W-40.
Required amount of engine oil:

Oil change: 850 ml
Oil filter change: 950 ml
Overhaul: 1 300 ml
Start up the engine and allow it to run for several minutes at

idling speed.
Shut down the engine and wait about two minute. Then check
the oil level in the oil level window. The motorcycle must be in
a level, upright position for accurate measurement. If the
level is below the “F” mark, add oil until the level reaches the
“F” mark.
ENGINE OIL FILTER

Clean initial 1 000 km and every 5 000 km
Replace the oil filter in the following manner:

Drain the engine oil by removing the drain plug.
Remove the two screws securing the filter cap.
Take off the cap 1 , and pull out the filter 4 .
Replace with the new engine oil filter.
Before installing on the filter, check to be sure that the O-
ring 5 is properly installed.
Before putting on the filter cap 1 , make sure that spring
3 and o-rings 2 are installed correctly.
Install the filter cap 1 and tighten the screws securely.
Add the engine oil and inspect the engine oil level.
CAUTION
When reassembly the oil filter, make sure to check the

oil filter installed as shown in illustration. ⑤
If the filter is installed improperly, serious engine
damage may result.
2-7

OIL SUMP FILTER

Clean every 10 000 km
Clean the sump filter to remove any foreign matter that may be
collected there. Inspect the screen to insure that it is free of
any sign of damage.
CLUTCH
4mm
Inspect initial 1 000 km and every 5 000 km.
The clutch play should be 4 mm as measured at the clutch

lever holder before the clutch begins to disengage. If the play
in the clutch is incorrect, adjust it in the following way:
Loosen the lock nut 1 and screw the adjuster 2 on the
clutch lever holder all the way in.
Loosen clutch cable adjuster lock nut 3 .
Turn the clutch cable adjuster 4 in or out to acquire the
specified play.
Use the adjuster 2 for minor adjustment.
Tighten lock nut while holding the adjuster in position.
CAUTION
Excessive clutch cable play makes clutch dragging

easily lead to the damage or wear of the clutch and gear
shifting mechanism.
CARBURETOR
Stable carburetor performance is the basis requirement for

engine. The carburetor is pre-set at the factory for the best
carbureting. Do not attempt to alter its setting. There are two
items of adjustment, engine idle speed and throttle cable play.
IDLING ADJUSTMENT
Start up the motorcycle, maintain the low engine speed until
the motorcycle is preheated fully.
After preheating , set its speed at anywhere between 1 400
and 1 600 r/min by turning adjust screw.
Engine idle speed: 1500±100 r/min

CAUTION
Make this adjustment when the engine is hot.
2-8

THROTTLE CABLE PLAY

To adjust the throttle cable play to be 0.5-1.0 mm.
Loosen the locking nut 1 , turn the adjuster 2 so that the

throttle grip has 0.5 -1.0 mm play.
Tighten the locking nut 1 . 0.5-1.0mm
WARNING
After adjustment is completed, checked that handlebar

movement does not raise engine idle speed and that the
throttle grip returns smoothly and automatically.
FUEL HOSE
Inspect initial 1 000 km and every 5 000 km. Replace
every 4 years.
Inspect the fuel hose 1 and connections for damage and fuel
leakage. If any defects are found, the fuel hose must be
replaced.
FUEL STRAINER
Clean initial 1 000 km and every 5 000 km.
After fuel strainer removed, the fuel strainer should be

throughly blown by compressed air from its interior to its
exterior.
The fuel strainer should be inspected and cleaned periodically.
If the fuel strainer is damaged, replace it immediately.
Filter bowl
Fuel filter
Seal ring
2-9

DRIVE CHAIN
Clean and lubricate every 1 000 km
Clip opening direction
DRIVE CHAIN / SPROCKET

Visually inspect the drive chain for the below listed possible
malconditions. (Lift the rear wheel by placing the center stand,
and turn the rear wheel slowly by hand with transmission in
NEUTRAL.)
1. Loose pins 2. Damage rollers
3. Rusted links 4. Twisted or seized links
5. Excessive wear
If any defects are found, the drive chain must be replaced.
Damage to the drive chain means that the sprockets may also
be damaged. Inspect the sprockets for the following:
1.Excessively worn teeth
2.Broken or damaged teeth
3.Loose sprocket mounting nuts Excessive
Normal
wear
Cleaning and Lubrication
After throughly washing the drive chain with detergent liquid
and allowing it to dry, lubricate the drive chain with chain lube
or new engine oil.
Drive Chain Adjustment

Adjust the drive chain slack to the proper specification. The
drive chain may require more frequent adjustment than
periodic maintenance schedule depending upon your riding
conditions.
WARNING
Too much chain slack can cause the chain to come off
the sprocket, resulting in an accident or serious
damage to the motorcycle. Inspect and adjust the drive
chain slack before each use.
Place the motorcycle on center stand.
Loosen rear axle nut 4 .
Loosen the right and left lock nuts 2 .
Loosen or tighten both chain adjuster bolts 1 till there is 10-
20mm of slack at the middle of the chain between engine
and rear sprockets. The mark 3 on both chain adjusters 5
must be at the same position on the scale to ensure that
10-20 mm
front and rear wheels are correctly aligned.
After adjusting the drive chain, tighten rear wheel axle nut
4 to the specified torque.
Check the rear brake pedal travel. (Refer to page 2-14)
Rear axle nut: 50-80 N • m

123 20 21 22
CHAIN WEAR
Count out 21 pins on the chain and measure the distance 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29
between. If the distance exceeds 259.4 mm, the chain must be 0 1 2 3 4 5 6 7 8
replaced.
Drive chain 20 pitch length limit: 259.4 mm
09900-20103 : Vernier caliper
2-10

BRAKES
Inspect initially at 1 000 km and every 5 000 km. UPPER
Replace hose every 4 years.
Change fluid every 2 years.
LOWER
FRONT BRAKE(DISC TYPE)
Brake fluid level
Support the motorcycle body on the center stand, and place
the handlebars straight.
Check the brake fluid level by observing the lower level line
on the brake fluid reservoir.
When the level is below the lower level line, replenish with
brake fluid that meets the following specification.
Specification and classification: DOT 3 or DOT 4

WARNING
Brake fluid is harmful or fatal if swallowed, and harmful
if it comes in contact with skin or eyes. If brake fluid is
swallowed, immediately contact a poison control
center or a physician. If brake fluid gets in eyes, flush
eyes with water and seek medical attention. Do not
wash the master cylinder with high pressure water.
CAUTION
The brake system of this motorcycle is filled with a

glycol-based brake fluid. Do not use or mix different
types of fluid such as silicone-based or pertroieum-
based. Do not use any brake fluid taken from old, used
or unsealed containers. Never re-use brake fluid left
over from the last servicing or stored for a long period.
FRONT BRAKE DISC AND FRONT BRAKE PADS

Check the thickness 1 of front brake disc, replace the front
brake disc with new one if the thickness is less than 3.5mm.
The extent of brake pad wear can be checked by observing the
grooved limit line 2 on the pad. When the wear exceeds the
grooved limit line, replace the pads with new ones.
WARNING
Do not drive the motorcycle immediately after the
replacement of the new brake disc or brake pads.
Squeeze and release the brake lever several times to
make the mating of brake disc and brake pads
completely and circulation of brake fluid stably. The
brake distance is longer than the original distance
after the replacement of new brake disc or brake pads.
After 300 km of driving, the motorcycle will get the
best break performance. Before that, Keeping enough
brake distance is necessary during the driving.
2-11

AIR BLEEDING THE BRAKE FLUID CIRCUIT

Air trapped in the fluid circuit acts like a cushion to absorb a
large proportion of the pressure developed by the master
cylinder and thus interferes with the full braking performance
of the caliper brake. The presence of air is indicated by
"sponginess" of the brake lever and also by lack of braking
force. Considering the danger to which such trapped air
exposes the machine and rider, it is essential that, after
remounting the brake and restoring the brake system to the
normal condition, the brake fluid circuit be purged of air in the
following manner:
Fill up the master cylinder reservoir to the upper line.
Replace the reservoir cap to prevent entry of dirt.
Attach a pipe to the caliper bleeder valve, and insert the free
end of the pipe into a receptacle.
Squeeze and release the brake lever several times in rapid
succession, and squeeze the lever fully without releasing it.
Loosen the bleeder valve by turning it a quarter of a turn so
that the brake fluid runs into the receptacle; this will remove
the tension of the brake lever causing it to touch the
handlebar grip. Then close the valve, pump and squeeze the
lever, and open the valve.
Repeat this process until the fluid flowing into the receptacle
no longer contains air bubbles.
CAUTION
Replenish the brake fluid reservoir as necessary while

bleeding the brake system. Make sure that there is
always some fluid visible in the reservoir.
Close the bleeder valve, and disconnect the pipe. Fill the
reservoir to the "upper” level line.
CAUTION
Handle the brake fluid with care: the fluid reacts

chemically with paint, plastics, rubber materials, etc.
FRONT BRAKE LIGHT SWITCH

Squeeze the front brake lever to inspect the brake light switch.
If the brake light switch works inflexible, inspect, adjust or
replace.
2-12

REAR BRAKE
Rear brake pedal height
Adjust the brake pedal limit screw 1 to set the brake pedal at
the position of 10-20mm higher than the footrest, then tighten
the locking nut.
Rear brake pedal height H : 10-20 mm
Rear brake pedal travel

Rear brake travel 2 is the distance from stepping on the brake
pedal until the brake begins taking effect .
Turn the rear brake adjuster 3 to adjust the travel 2 to 20-30
mm.
Brake pedal travel 2 : 15~25 mm
REAR BRAKE LINING WEAR LIMIT
The motorcycle is equipped with brake lining wear limit

indicator on rear brakes. To check wear of the break lining,
follow the steps below.
Check if the brake system is properly adjusted first.
While operating the brake, check to see the extension line 11
from the index mark 2 is within the range on the brake panel.
If the index mark is outside the range as shown in the
illustration at right, the brake shoes should be replaced to
ensure safe operation.
REAR BRAKE LIGHT SWITCH
Adjust rear brake light switch so that brake light will come on
just before a pressure is felt when the brake pedal is stepped.
2-13

TIRES
Check the tire pressure and surface during the maintenance.

There are serial marks 1 T.W.I. (Tire Wear Indicator) in the
edge of the tire. Check the block 2 of T.W.I. in the tread near
the mark. If the tire wears off to reach the boss, the tire should
be replaced.
Check the damage 3 (punctures or fractures) on the tire
surface visually. As surface damage may impede driving
stability, such tires should be replaced.
TIRE PRESSURE
SOLO RIDING DUAL RIDING

COLD INFLATON
TIRE PRESSURE Kpa kg/cm 2 kpa Kg/cm 2
FRONT 175 1.75 175 1.75
REAR 200 2.00 225 2.25
CAUTION
Proper tire pressure and condition affect vehicle

performance. Please check the tire pressure and
surface condition periodically.
STEERING
Inspect initial 1 000 Km and every 5 000 Km
Steering stem bearings should be adjusted properly for smooth

turning of the handlebars and safe running.
Steering which is too stiff prevents smooth movement of
handlebar.
Steering which is too loose will cause vibration and damage to
the steering bearing. Check to see that there is no play in the
front fork attachment.
If the play is found, perform the steering bearing adjustment as
described in page 5-16 of this manual.
FRONT AND REAR ABSORBER

Inspect every 5 000 km.
FRONT ABSORBER
Grasp the front brake, squeeze the front absorber to check
it’s motion.
Check for leaks or damage. Replace damaged parts and
tighten all bolts and nuts.
2-14

REAR ABSORBER
Press the rear carrier, move the rear absorber up and down
four or five times to check for the noise or smooth movement.
Inspect the rear absorber spring for damage, deformation or
oil leakage.
LIGHTING AND SIGNAL

Inspect the headlight, left and right turn signal light, tail light /
brake light and dashboard signal light, replace the light if there
is something unusual. (Refer to page 6-7)
CHASSIS AND ENGINE MOUNTING BOLTS AND NUTS

The nuts and bolts listed are important parts, and they must be in good condition for safety. They must be
re-tightened, as necessary, to the specified torque with a torque wrench.
ITEM N•m Kg • m
1 Front axle nut 36-52 3.6-5.2
2 Front brake caliper mounting bolts 18-28 1.8-2.8
3 Brake hose union bolt 20-25 2.0-2.5
4 Front brake disc mounting bolts 18-28 1.8-2.8
5 Front absorber cap bolts 35-55 3.5-5.5
6 Handlebar clamping bolts 12-20 1.2-2.0
7 Steering bolt 35-55 3.5-5.5
8 Lower bracket bolts (front absorber clamp bolts) 25-35 2.5-3.5
9 Rear absorber fitting nuts 22-35 2.2-3.5
10 Rear axle nut 50-80 5.0-8.0
11 Rear brake cam lever bolt 6-8 0.6-0.8
12 Rear torque link bolts 10-16 1.0-1.6
13 Engine mounting bolts 33-39 3.3-3.9
14 Engine hanging nuts 22-33 2.2-3.3
15 Rear swing arm shaft nut 50-80 5.0-8.0
16 Exhaust pipe bolt 11-15 1.1-1.5
2-15

2-16

2-17
COMPRESSION PRESSURE
Cylinder compression is an indicator of its inner state. The necessity of repair depends on the result of
inspection. The record of your authorized maintenance dealer should include compression pressure
readings obtained in every maintenance.
NOTE:
* Before testing the engine for compression pressure, make sure that the cylinder head nuts
and bolts are tightened to specified torque values and valves clearance are properly adjusted.
* Have the engine warmed up by idling before testing it.
* Ensure that the battery is fully charged.
Remove related parts and inspect compression pressure in the following process:
Support the motorcycle with the main stand;
Remove spark plug;
Fit pressure gauge① and adapter ② to the spark plug
1
hole, pay attention to connector tightening;
Turn throttle to full opening;
Electrically start the motorcycle, take the maximum
2
reading in the recording as cylinder compression pressure.
①
1 Compression gauge 09915-64512
②
2 Adapter 09915-63310
Compression pressure
Standard Limit
2 2
10-14 kg/cm 8 kg/cm
A low compression pressure may indicate any of the following malfunctions:

Excessively worn cylinder wall.
Worn piston or piston rings.
Piston rings stuck in the grooves.
Poor seating contact of valves.
Defective cylinder head gasket.
When the compression pressure noted is down to or below the limit indicated above, the engine must be
disassembled, inspected and repaired as required.
2-17

2-18
OIL PRESSURE
Inspect every 5 000 km
Periodically inspect oil pressure of engine so as to ascertain the state of moving parts.
Oil pressure inspection procedure

Support the motorcycle with the main stand;
Install the oil pressure gauge in the position shown in the
illustration.
Warm up the engine as follows.
Summer: approx. 10 min. at 2 000 r/min.
Winter: approx. 20 min. at 2 000 r/min.
After the warming up operation, increase the engine speed to
3 000 r/min, and read the oil pressure gauge
③Oil pressure gauge 09915-74510
Oil pressure specification

Above 10 kPa (0.1kg/cm2)
at 3,000rpm, Oil temperature 60
Below 30 kPa (0.3kg/cm2)
A low oil pressure may indicate any of the following malfunctions:

Engine strainer clogging
Oil leakage at oil hole
O-ring damage
Engine oil pump damage
Any concurrence of the above
A high oil pressure may indicate any of the following malfunctions:

Excessive viscosity of engine oil
Oil hole clogging
Any concurrence of the above
2-18

ENGINE
CONTENTS
REMOVABLE ENGINE PARTS WITH ENGINE IN PLACE 3-1

ENGINE REMOVAL AND REMOUNTING 3-2
CYLINDER HEAD AND VALVE 3-6
CYLINDER AND PISTON 3-17
CLUTCH 3-21
OIL PUMP 3-25
GEAR SHIFTING SHAFT
GENERATOR AND STARTING CLUTCH

3-26
3-27
3
CRANKSHAFT, TRANSMISSION AND KICK STARTER DEVICE 3-31

ENGINE
REMOVING ENGINE PARTS WITH ENGINE IN PLACE
UPPER SIDE OF ENGINE

Chain tensioner 3-6
Cylinder head cover 3-6
Cam shaft 3-7
Cylinder head 3-7
Cylinder 3-17
Piston 3-17
RIGHT SIDE OF ENGINE

Oil filter 3-21
Clutch cover 3-21
Clutch 3-22
Oil pump 3-25
Gear shifting shaft 3-26
LEFT SIDE OF ENGINE

Sprocket cover 3-27
Starting motor 3-27
Generator rotor 3-27
Starting clutch 3-28
Generator stator 3-28
Trigger coil 3-28
3-1

ENGINE
ENGINE REMOVAL AND INSTALLATION

ENGINE REMOVAL
Before taking the engine out of the frame, wash the engine
with a suitable cleaner. The procedure of engine removal is
sequentially explained in the following steps:
Support the motorcycle with main stand.
Drain the engine oil.
Remove the left and right seat mounting bolts and left rear
shock absorber nut, then take off the seat.
Remove the left and right side cover .

Remove the battery lead.
Turn off the fuel switch, remove the fuel hose.
Disconnect the fuel gauge coupler.

Take off the fuel tank by removing the mounting bolts 1 .
Take off the clutch cable by removing the clutch lever bolt
2 and adjuster lock nut 3 .
3-2

ENGINE
Remove the generator and gear indication light coupler 5

and 6 .
Disconnect the carburetor balancer pipe 7 by unscrewing

the clamp screws.
Loosen the throttle cable adjuster lock nuts, and take off the
throttle cable 8 .
Remove the crankcase breather pipe 9 .

Remove the speedometer cable mounting screw, take off the
speedometer cable assembly 10.
Take off the engine sprocket cover 11 .

Disconnect the ground wire 12 from the crankcase.
Take off the drive chain by removing the clip 13 .
3-3

ENGINE
Remove the lead wire 14 of starter motor wire.

Take off the spark plug cap 15 .
Remove the muffler mounting bolt 16 .
Remove the muffler mounting bolts 17 , then take off the

muffler.
Remove the engine front mounting bolt 18 and engine lower

hanging plate bolt 19 , take off the engine lower hanging
plate.
Remove the engine upper mounting bolt 20 and rear lower
mounting bolt 21 .
Remove the rear swing arm shaft nut 22, draw out the rear
swing arm shaft, take out the engine from the right side.
The engine must be taken out from the right side .
Be careful not to draw out the swing arm pivot

shaft completely from the left side swing arm pivot
hole , Insert the shaft or rod into the right side pivot
hole from the right side of the frame to keep the
alignment of the frame holes and swing arm pivot
holes.
3-4

ENGINE
ENGINE REMOUNTING
The engine can be mounted in the reverse order of removal.
Temporarily fasten the engine mounting bracket before

inserting the engine mounting bolts.
NOTE :
The engine mounting nuts are self-lock nuts. Once the nut
has been removed, it is no longer of any use. Be sure to
use new nuts and tighten them to the specified torque.
Tightening torque for engine mounting bolts:
Engine mounting nut A : 33-39 N•m

Engine lower hanging nut B : 22-33 N•m
Swing arm nut C :50-80 N•m D
Muffler bolt D :11-15 N•m
Install the drive chain and drive chain clip 1 .
Align the release arm slit surface with the notch mark on the
release cam shaft.
Notch mark
Slit
After installing the engine, pour the engine oil into the
engine. (Refer to page 2-7)
Inspect the oil level. (Refer to page 2-7)
Inspect the throttle cable (page 2-9)
Inspect the clutch cable (page 2-8)
Inspect the idling speed (page 2-8)
Inspect the drive chain (page 2-10)
3-5

ENGINE
CYLINDER HEAD AND VALVE

REMOVAL
Drain the engine oil, take off the engine. (Refer to page 3-2)
Remove the generator cover cap 1 and valve timing inspect-
ing plug 2 .
Remove the valve inspecting caps 3 .
Bring the piston to top dead center.
When removing cylinder head cover , piston must be

at top dead center on compression stroke.
Remove the camshaft chain tensioner 4 .
Loosen the cylinder head cover bolts diagonally.

Do not remove
Remove the cylinder head cover.
3-6

ENGINE
Remove the camshaft sprocket bolts and detach the cam-

shaft.
The cam chain tensioner bolt A is to be removed

only when disassembling the engine .
Do not drop camshaft drive chain, pin and sprocket into

the crankcase.
Remove the cylinder head side nuts and cylinder side nuts.
Loosen the cylinder head cover nuts diagonally, then detach

the cylinder head.
If it is difficult to remove the cylinder head , gently pry it

off while tapping the finless portion of the cylinder
head with a plastic hammer . Be careful not to break the
fins.
DISASSEMBLY
Remove the rocker arm shaft set bolts.
Pull out the rocker arm shafts with pliers, remove the spring
and spring washer.
3-7

ENGINE
Take off the valve cotters from the valve stem.
11F14 - 018: Valve spring tools
Take out the valve spring retainers , inner springs and

outer springs.
Pull out the valves from the other side.
Remove the oil seal.
Removed oil seal should be replaced with a new one.
Remove the spring lower retainer.
INSPECTION
CYLINDER HEAD COVER
After removed the sealant from the fitting surface of the
cylinder head cover, place the cylinder head cover on a plain
plate and check for distortion with a thickness gauge. Check
points are shown in Fig. If the distortion exceeds the limit,
replace the cylinder head cover.
Cylinder head distortion limit: 0.05 mm
09900 - 20803 : Thickness gauge
ROCKER ARM SHAFT

Measure the diameter of rocker arm shaft.
Rocker arm shaft O.D. (IN and EX): 11.977-11.995 mm
09900-20205 : Micrometer (0-25 mm)
3-8

ENGINE
ROCKER ARM
Check the inside diameter of the valve rocker arm and wear
of the camshaft contacting surface.
Rocker arm shaft O.D. (IN and EX): 12.0-12.018 mm

09900 - 20605: Caliper gauge
CAMSHAFT
The camshaft should be checked for runout and also for
wear of cams and journals if the engine has been noted
to produce abnormal noise or vibration or a lack of output
power.
Worn-down cams are often the cause of mistimed valve H
operation resulting in reduced output power. The limit of cam
wear is specified for both intake and exhaust cams in terms of
cam height H , which is to be measured with a micrometer.
Replace camshafts if found it worn down to the limit.
Cam height H limit: IN.: 33 . 35mm EX.: 33.0 mm
09900-20202: Micrometer (25-50 mm)
CAMSHAFT JOURNAL WEAR

Determine whether each journal is worn down to the limit or
not by measuring camshaft journal oil clearance with the
camshaft installed.
Use the plastigage to read the clearance at the widest
portion, install the cylinder head cover and tighten the
cylinder head cover bolts to the specified torque.
Remove the cylinder head cover and measure the width of
the compressed plastigage using the envelope scale. This
measurement should be taken at the widest part of the
compressed plastigage.
Camshaft journal oil clearance limit: 0.15 mm
09900-22302: Plastigage (0.051 – 0.152 mm)
If the camshaft journal oil clearance measured exceeds the

limit, measure the outside diameter of camshaft.
Replace either the cylinder head set or the camshaft if the
clearance is incorrect.
Camshaft journal O.D.: 21.970-21.991 mm
09900-20205: Micrometer (0-25 mm)
3-9

ENGINE
Measure the runout with a dial gauge . Replace the cam-

shaft if the runout exceeds the limit.
Camshaft runout limit: 0.1 mm
09900-20606: Dial gauge (1/100 mm)

09900-20701: Magnetic stand
09900-21304: V-block ( 100 mm)
VALVE SPRING
Measure the valve spring free length.
Valve spring free length imit:

IN.: 31.24 mm EX.: 33.58 mm
09900 - 20103: Vernier calipers
CYLINDER HEAD
Check the spark plug hole and valve of combustion chamber
part for scratch.
Check the gasketed surface of the cylinder head for distor-
tion with a straightedge and thickness gauge.
Cylinder head distortion limit: 0.05 mm
09900-20803:Thickness gauge
VALVE STEM
Check the valve stem for bending, pitting or abnormal wear.
Measure the valve stem O.D.
Valve stem O.D.:

IN.: 4.975-4.99 mm EX.: 4.955-4.97 mm
09900-20205 : Micrometer (0~25 mm)
Measure the thickness A , and if the thickness is found to

have been reduced to the limit, replace the valve.
Valve face thickness limit: 0.5 mm
Visually inspect each valve for wear of its seating A

face. Replace any valve with an abnormally worn face.
3-10

ENGINE
Support the valve with “V” blocks as shown, and check its
runout with a dial gauge. The valve must be replaced if the
runout exceeds the limit.
Valve stem runout limit: 0.05 mm
09900-20606: Dial gauge (1/100 mm)
09900-21304: V-block ( 100 mm)
Place the dial gauge at right angles to the valve head,

and measure the valve head radial runout. If it measures
more the limit, replace the valve .
Valve stem runout limit: 0.03 mm

09900-20606: Dial gauge (1/100 mm)
09900-21304: V-block ( 100 mm)
VALVE SEAT INSPECTION AND SERVICING

Throughly clean the the carbon deposits on the valves and
valve seat.
Coat the valve seat with Prussian Blue uniformly.
Hold the valve with valve lapper, fit the valve and tap the
coated seat with the valve face in a rotating manner in order
to obtain a clear impression contact.
09916-10911: Valve lapper set

The ring-like dye impression left on the valve face must be
continuous without any break.
The impression contact can be used to check the contact
o
surface institute, the contact position. 15 o 30
In addition, the width of the dye ring, which is the visualized

seat "width", must be within the specification. o
o 60
If any requirement is not met, correct the valve seat by 45
servicing it as follow steps.
CAUTION
The valve seat contact area must be inspected after INTAKE

each cut. 60
O
Do not use lapping compound after the final cut is

made. The finished valve seat should have a velvety 45 O
smooth finish but not a highly polished or shiny finish.
This will provide a soft surface for the final seating of valve seat
the valve which will occur during the first few seconds
of engine operation.
3-11

ENGINE
INTAKE EXHAUST EXHAUST

O O O O
Valve seat angle 30 , 45 15 , 45
Valve width 0.9-1.1mm
Intake side Exhaust side
45 o N-122 45 o N-122 valve seat

o o
30 N-126 15 N-121
o
60 N-111
09916-21110: Valve reamer set
Check the contact surface institute.

If found any defective, service the valve seat.
Damaged surface Uneven contact surface
o
Using the 45 reamer, descale and cleanup the seat with
one or two turns.
45 o
Check the contact position. If the contact face of the valve

is too high, finish it with 30 ° reamer to reduce the height.
30o
Contact surface is too high
If the contact face of valve is too low finish it with 60 °

reamer to increase the height.
Finish the valve seat surface again to standard range with
45 o reamer.
NOTE:
The valve seat position will affect the contact surface
60o
of valve, this is very important to the good sealing. Contact surface is too low
3-12

ENGINE
Check the contact width.
09900-20103: Vernier calipers

Valve seat width: 0.9-1.1 mm
Width
o
If contact width is too small, cut the valve seat with a 45
reamer to raise.
45 o
If the valve seat contact width is too big, cut the valve seat
out side 1/8 with a 30 o reamer and cut the bottom 1/8 with a
60 o reamer to lower.
Check the contact width.
o
If the width is out out off the specication, repeat the operation 30
above steps.
o
60
After the desired seat position and width is achieved, apply a

layer of lapping compound and use the reamer very lightly to
service the valve seat. After servicing, clean up the remaining
lapping compound on the cylinder head and valve.
Check the valve seat contact surface again.
If the lapping pressure is too big, valve seat will be

possibly distorted or damaged. Change the lapping
tool angel frequently to prevent valve seat surface
from being uneven. If the lapping compound get into
the middle of the valve and valve guide will possibly
lead to damage.
3-13

ENGINE
Clean and assemble cylinder head and valve components.

Fill intake and exhaust ports with gasoline to check for
leaks and worn seals.
If any leaks occur, check the valve seat and face for burrs or
other defects that could prevent the valve from fully seating.
Gasoline is very explosive, be sure to keep the work

area well ventilated. Keep away from fire and spark.
CYLINDER HEAD ASSEMBLY

Reassemble the cylinder head in the reverse order of
removal, pay attention to the following points:
Clean the cylinder head thoroughly with a cleaning

liquid and blow all passages with compressed air.
Oil each seal, and drive them into the position.
Always use new oil seal.
Lubricate all valves with Moly Paste.

Insert the valves into valve guide pipes.
M 99000-25140: MOLY PASTE

NOTE:
When a valve spring is mounted, the seal ring side should face
the combustion chamber. In order to avoid oil seal damage,
the valve oil seal should be mounted while the valve is rotating
slowly.
Install the valve spring washer, inner spring, outer spring

Large-pitch
and retainer.
Close-pitch
Install valve springs , making sure that the close-

Large-pitch
pitch end of each spring goes in first to rest on the head.
Close-pitch Cylinder
head
3-14

ENGINE
Install the valve cotters with the special tool.
11F14 - 018: Valve spring tools
CYLINDER HEAD COVER ASSEMBLY

Clean the cylinder head cover throughly with detergent.
Lubricate the rocker arm shaft with engine oil.
Mount the rocker arm, rocker spring, flexuous washer and
rocker arm to the cylinder head cover.
Tighten the rocker arm shaft set bolts to the specified torque.
REASSEMBLY
Reassemble the cylinder head in the reverse order of dis-
assembly, pay attention to the following points:
Clean up the cylinder head surface.
Do not let dirt and dust get into the engine.
Install the dowel pins 1 and cylinder head gasket.
3-15

ENGINE
Install the four nuts and washers, tighten the nuts to

specified torque. EX.
Cylinder head nut: 21-25 N•m

Copper washer Copper washer
IN.
Copper washer Copper washer
Install the four cylinder side nuts, tighten the nuts to the
specified torque.
Cylinder side nut: 8-12 N•m
Apply the Moly paste to the tip of cam .

Install the camshaft, sprocket and chain.
99000-25100: Moly paste
Bring the piston to top dead center before installing the

. camshaft and cam sprocket. Align the marks on the
camshaft so it is parallel with the surface of the
cylinder head. Apply Thread lock to the bolts.
99000-32030: Thread lock “1303"

Wipe up the oil on the cylinder head fitting surface.
Install the two dowel pins on the cylinder head.
Apply the Bond No. 1215 to the mating surface of cylinder
head. Pins
99000-31110: Bond No. 1215
Inspect the valve clearance. (Refer to page 2-5)
3-16

ENGINE
CYLINDER AND PISTON

CYLINDER REMOVAL
Remove the cylinder head. (Refer to page 3-7)
Remove the gasket, dowel pins and guide rod.
Remove the cylinder.
INSPECTION
Clean the remaining gasket on the cylinder surface .
Check the gasketed surface of the cylinder for distortion
with a stragihtedge and thickness gauge.
Cylinder distortion limit: 0.05 mm

09900-20803: Thickness gauge
Inspect the cylinder bore for wear or damage.

Measure the cylinder bore diameter at six places. If any one
of the measurements exceeds the limit, overhaul the
cylinder and replace the piston with an oversize, or replace
the cylinder.
Cylinder bore diameter limit : 57.135 mm
09900-20508: Cylinder gauge set
PISTON REMOVAL AND INSPECTION

REMOVAL
Place a clean rag over the cylinder base to prevent

piston pin circlip from dropping into crankcase.
Remove the piston pin circlip .

Remove the piston pin and piston with the special tool.
09910 - 34510: Piston pin remover

CAUTION
Hold the piston stably when taking out the piston pin
to prevent the damage to conrod big end bearing.
Remove the piston rings one by one by expanding the gap

symmetry.
When removing the piston ring, be careful not to

damage the piston. Do not expand the piston ring
excessively since it is apt to be broken down.
3-17

ENGINE
Decarbonize the piston.
Using a soft-metal scrapper or discarded piston ring

to decarbon the ring grooves of the piston. Do not use
the steel brush or the piston will be scratched.
INSPECTION
Temporary install the piston rings to the suitable position
with marked side upward.
Measure the clearance between the piston ring and groove
with a thickness gauge.
Piston ring-groove clearance limit:

1st: 0.180 mm 2nd: 0.150 mm
Measure the piston outside diameter at the place 8mm from

the skirt end with a micrometer.
Piston outside diameter limit: 8mm

56.844 mm at the 8 mm from the skirt end
09900-20203: Micrometer (50~75 mm)
Using a caliper gauge to measure the inside diameter of the

piston pin bore.
Piston pin bore inside diameter limit: 14.03 mm
09900-20605: Caliper gauge
Using a micrometer to measure the piston pin O.D..
Piston pin O.D.: limit: 13.98 mm
09900-20205: Micrometer (0-25)
3-18

ENGINE
Measure the conrod small end I . D .
Conrod small end I.D.: limit: 14.04 mm
09900-20605: Caliper gauge
Fit the rings in the cylinder, and measure each ring end gap
with a thickness gauge. If any ring has an excess end gap,
replace the ring.
Piston ring end gap limit:
1st: 0.50 mm 2nd: 0.50 mm
09900-20803 : Thickness gauge
Make sure to fit the piston ring in the cylinder evenly

with the piston head.
REASSEMBLY
Install the piston and cylinder in the reverse order of removal.
Pay attention to the following points:
Clean the top, skirt or groove of the piston.
CAUTION 1 20
12
0 120
Hold each piston ring with the piston rings properly

spaced and insert them into the cylinder.
Check to insure that piston rings are properly inserted
in the the cylinder skirt.
Carefully fit the piston rings to the piston with marked

side to the top.
Be careful do not damage the piston ring and piston

when installing the piston ring. Make sure to position
the gaps of the top ring and 2nd ring as required.
The gaps of two piston rings should be staggered at 120°.
Install the piston rings in the order of oil ring, 2nd ring
and 1st ring. Do not align the gap of oil ring with
expander ring.
Piston rings should turn smoothly in the piston groove after

assembly.
3-19

ENGINE
Place a clean rag over the cylinder base to prevent piston pin
circlip from dropping into crankcase, and then fit the piston
pin circlip with long-nose pliers.
Replace with a new piston pin circlip to prevent circlip

slipping from position.
End gap of the circlip should not be aligned with the
cutaway in the piston pin bore.
When installing the piston , the indent on the piston head

must be located to the exhaust side .
Before assembling the cylinder head, apply oil to conrod big

end, small end and piston sliding part.
Install the dowel pins , then install the gasket.
To prevent oil leakage, do not use the used gasket

again, always use new one.
Hold each piston ring with their properly spaced and insert
them into the cylinder.
Check to insure that the piston rings are properly inserted
into the cylinder skirt.
NOTE:
When mounting the cylinder , after attaching camshaft 2
drive chain , keep the camshaft drive chain taut, The
camsahft drive chain must not be caught between cam
drive chain sprocket and crankcase when crankshaft is
rotated.
There is a holder for the bottom end of the cam chain
guide cast in the crankcase. Be sure that the guide is
inserted properly or binding of the cam chain and guide
may result.
Install the cylinder head. (Refer to page 3-15)
3-20

ENGINE
CLUTCH
REMOVAL
Drain the engine oil .
Remove the oil filter cover nuts, take off the oil filter cover .1
Remove the oil filter.
Remove the clutch cover screws diagonally, take off the

clutch cover 2 .
Remove the gasket and dowel pins.
Remove the clutch spring bolts diagonally.
Remove clutch pressure plate 4 , washer 5 , bearing 6 and

clutch push block 7 .
Remove the clutch push rod 8 .
3-21

ENGINE
Remove the clutch drive plates and driven plates.
Flatten the lock washer..

Hold the clutch hub with the special tool, remove the clutch
hub nut and lock washer.
09920-53710: Clutch sleeve hub holder
Remove the clutch hub and washer.
Remove the primary driven gear, spacer and washer.
INSPECTION
Measure the thickness and claw width of each drive plate
with vernier calipers. Replace the drive plates found to have
worn down to the limit.
Drive plate thickness limit: 2.6 mm

Checking thickness
3-22

ENGINE
Drive plate claw width limit: 11.0 mm
Checking claw width
Measure each driven plate for distortion with a thickness

gauge. Replace all driven plates if any of them exceeds the
limit.
09900 - 20803: Thickness gauge
Driven plate distortion limit: 0.1 mm
Replace the drive and drive plates as a whole set which

Checking distortion
exceed the limit.
Measure the clutch spring free length.
Clutch spring free length limit: 29.45 mm
09900 - 20103: Vernier calipers
Replace all the springs if any spring is not within the

limit.
Inspect the clutch release bearing for any abnormality, parti-

cularly cracks, to decide whether it can be reused or should
be replaced.
Smooth engagement and disengagement of the clutch de-
pend on the condition of this bearing.
Primary driven gear is composed as shown.

1 Primary driven gear 4 Rivet
2 Damper 5 Clutch housing
3 Plate
If the internal damper wears , the play is generated between
gear and housing, causing abnormal noise. If the play is too
big, replace the primary driven gear assembly with a new one.
3-23

ENGINE
REASSEMBLY
Reassemble the clutch in the reverse order of removal, pay
attention to the following points:
Install the washer, spacer, primary driven gear assembly,
washer and clutch drive hub.
Install the lock washer, tighten the clutch sleeve hub nut to
the specified torque.
Clutch sleeve hub nut: 30-50 N·m
09920 - 53710: Clutch driven hub holder
Bend the clutch sleeve hub washer to the nuts.

Install the clutch drive plates and driven plates.
Install the drive plates as shown in the illustration.
Install the clutch push rod, push piece, bearing, washer and
pressure plate.
Install the clutch spring, tighten the clutch spring bolts dia-
gonally.
CAUTION
Set the marked side of clutch spring faces outside.
Install a new gasket and pins.

Install the clutch cover, and tighten clutch cover bolts dia-
gonally.
CAUTION
Use new gasket to prevent oil leakage.
Install a new oil seal ring.

Install the oil filter and oil filter cover.
Tighten three nuts.
Install and adjust clutch cable, and pour engine oil.(Refer to
page 2-8 and page 2-7)
3-24

ENGINE
OIL PUMP
REMOVAL
Remove the clip, oil pump driven gear and oil pump driven
gear pin.
Remove the oil pump.
INSPECTION
Rotate the oil pump by hand and check whether it moves
smoothly. If the oil pump does not move smoothly, replace it.
REASSEMBLY
Apply a small quantity of engine oil to the inside the oil pump
before assembly.
Apply theThread lock “1342” to the oil pump mounting bolts
and tighten the bolts.
99000-32050: Thread lock "1342"
3-25

ENGINE
GEAR SHIFTING SHAFT

REMOVAL
Remove gear shifting lever.
Remove the clutch. (Refer to page 3-20)
Remove the gear shifting shaft 1 .

Remove the screws, gear shifting cam guide plate 2 and 3 .
Remove the gear shifting driven gear 4 , pawl 5 , gear
shifting pawl pin 6 and return spring 7 .
INSPECTION
Check the return spring 7 for damage, gear shifting shaft 8
for wear or bending.
REASSEMBLY
Reassemble the gear shifting shaft in the reverse order of
removal, pay attention to the following points:
When installing the gear shifting pawls to the driven gear ,
the large shoulder A must face to the outside as shown.
Install the cam guide. Apply a small quantity of THREAD
LOCK “1342" to the threaded parts of the securing screws.
99000 - 32050: Thread lock “1342"
3-26

ENGINE
GENERATOR & STARTING CLUTCH

REMOVAL
Disconnect the generator coupler.
Remove the engine sprocket cover.
Remove the starting motor by removing the bolts.
Remove the generator cover

Remove the gasket and dowel pins.
Remove the generator rotor nut while holding the generator

rotor with the special tool.
11F14 - 001: Rotor holder
3-27

ENGINE
Remove the generator rotor and key with the special tool.
11F14-001: Rotor holder

11F14-003: M16 screw
11F14 - 005: Generator rotor remover M30
Do not damage the key slot and crankshaft when

removing the key.
Remove the starter clutch gear.
Remove the roller 1 , push piece 2 , and spring 3 from the

starting clutch.
Hold the generator rotor with the special tool, remove the
starting clutch bolt.
Do not remove the starting clutch unless necessary.
Remove the generator stator 4 .

Remove the trigger coil 5 .
3-28

ENGINE
INSPECTION
Install the starter driven gear to the starter clutch and turn
the starter driven gear by hand to inspect the starter clutch
for a smooth movement. The gear turns one direction only. If
a large resistance is felt to rotation, inspect the starter clutch
for damage or inspect the starter clutch contacting surface of
the starter driven gear for wear or damage. If they are found
to be damaged, replace them with new ones.
Inspect the starter clutch for wear, damage or abnormity

moving.
Replace the whole set of springs, if starter clutch

springs are removed.
REASSEMBLY
Reassemble in the reverse order of removal, pay attention to
the following points:
Install the stator 1 , cable pressure plate, apply the Thread
lock to the bolt and tighten it.
Install the trigger coil 2 , apply Thread lock to the screw
head and tighten it.
Apply bond to the grommet 3 groove.
99000 - 32050: Thread lock “1342"

99000-31140 : Bond ”1207B”
Clean the starter clutch, apply engine oil to the separate

ring, Fit the starter clutch on the rotor.
Apply the Tread lock to the starter clutch, tighten the bolts to
Starter clutch bolt: 8-12 N•m
99000-32030: Thread lock “1303"
3-29

ENGINE
Fit the key in the crankshaft key slot.
When installing the key, take care not to damage the key
slot and crankshaft.
When installing the rotor, align the rotor key slot with the key
on the crankshaft.
Install the generator nut, tighten the nut to the specified
torque.
Generator nut: 50-60 N•m
3-30

ENGINE
CRANKSHAFT, TRANSMISSION AND KICKSTARTERSET.

REMOVAL
Remove the cylinder head and cylinder. (Refer to page 3-7)
Remove the clutch and gear shifting shaft.(Refer to page 3-
21)
Remove the generator rotor and starting clutch. (Refer to
page 3-27)
Remove the neutral locate screw plug and oil filter cover.
Do not take off the neutral locating screw plug (inner

hexagon ) when drain the engine oil.
Clamp the conrod small end with conrod holder, remove

the lock washer, remove the primary drive gear lock nut.
09910 - 20116 : Conrod holder
Primary drive gear lock nut is left-hand nut.
Remove the gear shifting cam guide.

Remove the gear shifting cam driven gear assembly.
Remove the gear switch position screws, take off the gear
position switch, pin and spring.
Remove the two bolts, take off the drive shaft oil seal block
plate.
Remove the crankcase mounting bolts.
3-31

ENGINE
Fit the crankcase separator, so that the tool plate is parallel

with the end face of the crankcase.
Remove the right crankcase with the special tool.
09920-13120 : Crankcase separator
WARNING
The crankshaft and transmission components must

remain in the left crankcase half, This is necessary
because the gear shifting cam stopper is mounted on
the left crankcase half and will be damaged if the
transmission components remain in the right half.
Remove the gear shifting hub fixing spring.

Remove the gear shifting shafts, take off the forks.
Remove the gear shifting hub.
NOTE:
Two kinds of gear shifting forks, 1 and 2 , are used.
They resemble each other very closely in extermal
appearance and configuration. Carefully examine the
illustration for correct installing positions and
directions.
Remove the transmission assembly.
Remove the crankshaft with the special tool.
09920-13120: Crankcase separator
3-32

ENGINE
INSPECTION
Measure the big end of the conrod side clearance with a
thickness gauge.
Conrod big end clearance limit: 0.5 mm
Support the crankshaft with “V” blocks as shown.

Measure the crankshaft runout with the dial gauge.
Crankshaft runout limit: 0.05 mm
09900-20606: Dial gauge (1/100 mm)

09900-21304: V-block
Using a thickness gauge, check the shifting fork clearance in

the groove of its gear. If the clearance limit exceeds by any
gear, determine whether the gear or the gear shifting fork
should be replaced by measuring the thickness and groove
width.
Fork to groove clearance limit: 0.5 mm
09900-20803 : Thickness gauge Checking clearance
Measure the gear shifting fork thickness.
Fork thickness:
No.1 and 2: 4 .8-4.9 mm No.3: 5.3-5.4 mm
Checking thickness
Measure gear shifting groove width.
Gear shifting groove width:

No. 1 and 2 : 5 .1 mm No.3: 5.5-5.6 mm
Checking groove width
3-33

ENGINE
Inspect the gear shifting hub guide slot.

● Replace the gear shifting hub if the guide slot is damage.
Inspect each bush, gear inner surface and gear teeth face
for abnormal wear or poor lubrication.
Rotate the inner race by hand to inspect for an abnormal

noise and a smooth rotation and inspect to see if the outer
race is movable in the crankcase.
Replace the bearing if there is something unusual.
BEARING REMOVAL
Remove the bearing locating plates on left and right
crankcase.
Remove the crankshaft bearing, countershaft bearing and

driveshaft bearing with the special tool.
09921-20240: Bearing remover
3-34

ENGINE
REASSMEBLY
Reassemble in the reverse order of removal, pay attention
to the following points:
BEARING
Install the bearings on the left and right crankcase with the
special tool.
09913-70210: Bearing installer
CRANKSHAFT
Decide the width between the webs when rebuilding the

crankshaft.
Width between webs:
Standard: 52.9-53.1 mm
When mounting the crankshaft in the crankcase, it is

necessary to pull its left end into the crankcase.
09910 - 32812: Crankshaft installer
3-35

ENGINE
Never fit the crankshaft into the crankcase by

striking it with a plastic hammer .
Always use the special tool , otherwise crankshaft
alignment accuracy will be affected.
TRANSMISSION
Never reuse a circlip. After a circlip has been

removed from a shaft, it should be discarded and a new
circlip must be installed. When installing a new circlip,
care must be taken not to expand the end gap larger
than required to slip the circlip over the shaft. After
installing a circlip, always insure that it is completely
seated in its groove and securely fitted.
3-36

ENGINE
Press-fit 2nd drive gear onto the counter shaft. Before

reassembling, coat the internal face of the 2nd drive gear
with Thread Lock super “1303B”and install it so that the
length A as shown in Fig.
Countershaft length A : 87.8-88.1 mm

99000-32030: Thread lock super "1303"
A
The procedure may be performed only twice before

shaft replacement is required.
GEAR SHIFITNG HUB AND FORKS
Fit the gear shifting hub on the crankcase.

Position the hub as shown in Fig. so that the gear shifting
forks can be installed easily.
3-37

ENGINE
NOTE:
Two kinds of gear shifting forks, 1 and 2 , are used.
They resemble each other very closely in extermal
appearance and configuration. Carefully examine the
illustration for correct installing positions and
directions.
CRANKCASE
Coat Super Grease “A” to the lip of oil seals.
Remove sealant material on the fitting surfaces of right and
left halves of crankcase and thoroughly remove oil stains.
Fit dowel pins on the left halt.
Apply engine oil to the big end of the crankshaft and all parts
of the transmission gears.
Apply Bond No. 1215 uniformly to the fitting surface of the
left half of the crankcase, and after waiting a few minutes, fit
the right half on the left half.
A 99000 - 25010: Super grease “A”

99000-31110: Bond No.1215
After the gear shifting hub driven gear, guide, shifting

shaft and neutral stopper have been fitted, confirm that
gear change is normal while turning the countershaft
and driveshaft. If gear change is not obtained, it means
that assembly of gears or installation of gear shifting
fork is incorrect. If this is th e case, disassemble and
trace the mistake.
Hold the conrod small end with conrod holder, tighten the
primary drive gear nut to the specified torque. Bend the
washer to the primary drive gear nut.
Primary drive gear nut: 40-60 N•m
09910 - 20116: Conrod holder
Install the generator and starting clutch. (Refer to page 3-30)

Install the clutch and gear shifting shaft. (Refer to page 3-24
and 3-26)
Install the cylinder and cylinder head. (Refer to page 3-20
and 3-15)
Install the engine, and add the oil. (Refer to page 3-6)
3-38

FUEL AND LUBRICATION
CONTENTS
FUEL COCK 4-1

CARBURETOR 4-3
LUBRICATION SYSTEM 4-7

FUEL AND LUBRICATION SYSTEM
FUEL COCK AND FUEL FILTER

REMOVAL
Turn the fuel cock to ” ” position shown in photo and
disconnect fuel hose from the fuel cock.
Place a clean pan under the fuel cock assembly, turn fuel
cock to “ ” position and drain the gasoline.
WARNING
Gasoline is very explosive. Extreme care must be used.
Remove the fuel filter.
Remove the fuel cock.
CLEANING
Clean filter with compressed air and inspect for cracks.
Replace the fuel filter with a new one if it is damage or crack.
Rust from the fuel tank tends to build up in the filter, which,
when the filter has been neglected for a long period, inhibits
the flow of fuel. Remove the rust from the filter using
compressed air.
4-1

REASSEMBLY
Reassemble the fuel cock or fuel filter in the reverse order of
removal. Pay attention to the following points:
Gasket
Install the fuel cock.

WARNING
Gasket must be replaced with a new one to prevent

leakage.
Install the fuel filter.
Do not miss to install the O-ring C during the remounting.
A Filter cup
B Fuel filter
C O-ring
4-2

CARBURETOR
CARBURETOR CONSTRUCTION
B
A
C
D
F
E
ITEM SPECIFICATION ITEM SPECIFICATION
Carburetor type BS26 Bubbling jet D Ø3
I.D. No. 054G Main jet E # 110
Needle A 4DH41-2 Idle air screw F 2,5/8 turn out
Needle jet B P -0(390) Idle air jet G # 1.25
Idle jet C # 12.5 Idle 1400 ± 100 r/min
4-3

REMOVAL AND DISASSEMBLY

Disconnect the carburetor balance pipe 1 .
Remove the carburetor clamp screw 2 .
Remove the throttle cable 3 .

Remove the fuel hose 4 .
Remove the carburetor.
Remove the carburetor diaphragm cover.
Remove the spring, diaphragm and piston.
Remove the float chamber body.
4-4

Remove the float pin screws.

Pull out the float pin and remove the float and needle valve.
Remove the main jet A . A

Remove the Bubbling jet B .
Remove the idle jet C . B
C
NEEDLE VALVE INSPECTION

If foreign matter is caught between the valve seat and the
needle, the gasoline will continue flowing and cause it to
overflow.
Clean the float chamber and float parts with gasoline, if the
needle is worn as shown in the illustration, replace it together
with a valve seat. Clean the fuel passage of the mixing
chamber with compressed air.
REMOUTING AND REASSEMBLY

Reassemble the carburetor by reversing the sequence of
disassembling steps.
When installing the floating chamber, make sure to fit the

seal ring correctly.
Replace the O-ring with a new one when installing the

float chamber.
4-5

REMOUNTING
Remount the carburetor by reversing the sequence of removal
steps, and following adjustments and inspection are
necessary after remounting the carburetor.
THROTTLE CABLE PLAY 2 1

Adjust the throttle cable play A to be 0.5-1.0 mm.
A
Adjust the throttle cable play as follows .
Slide the boot, loosen the lock nut 1 of the throttle pulling
cable, turn the adjuster 2 clockwise or counterclockwise
until the throttle cable play (at the throttle grip) is between
0 . 5-1 . 0 mm.
Tighten the lock nut 1 after adjusting the play,
Recheck that handlebar movement does not raise the
engine idle speed and that the throttle grip returns smoothly
and automatically.
Throttle cable play: 0.5~1.0 mm
IDLING ADJUSTMENT
If engine running is needed in work, be sure to keep the

work area well ventilated. Do not run engine in an
closed space. In engine exhaust gas, there is carbon
monoxide that leads to loss of consciousness or leads
to death.
Engine running is allowable only at a well ventilated
place or in an enclosure with exhaust gas discharge
system.
Idle air screw is factory-installed and set. Adjustment

is not necessary unless carburetor needs to be
disassembled for inspection or screws need to be
replaced. For accurate adjustment, a ten-minute
engine preheating is necessary.
Turn in the idle air screw until it lightly seats , then back
it out the pre-set turns.
Pre - set: 2, 5/8 turns back
Start the engine, preheat it under idle running condition.
Adjust the idle speed by means of the pilot screw.
Engine idle speed: 1 500 ± 100 r/min

Slowly and repeatedly adjust the idle air screw to obtain
maximum engine speed.
Adjust idle speed to specified value by means of pilot screw.
In case of unstable engine running, repeat till the engine
running is easy and stable.
4-6

LUBRICATION SYSTEM
Camshaft journal Conrod small end bearing

and cam face
Rocker arm shaft Camshaft Cylinder wall
Conrod big end bearing
Clutch release cam
Countershaft bearing Oil filter

Driveshaft bearing
Countershaft and By pass

gears

Drive
shaft and gears Oil pump
Primary driven gear

spacer
Sump filter
Clutch plates
OIL PAN
4-7

CHASSIS
CONTENTS
FRONT WHEEL 5-1
FRONT ABSORBER 5-6
STEERING STEM 5-12
FRONT BRAKE
REAR WHEEL AND REAR BRAKE

5-18
5-24
5
REAR ABSORBER AND REAR SWING ARM 5-30

CHASSIS
FRONT WHEEL
CONSTRUCTION
Front axle Front tire

Spacer 10 Front rim Item N•m kgf•m
Dust seal 11 Speedometer gear driver A 18-28 1.8-2.8
Washer 12 Oil seal B 36-52 3.6-5.2
Brake disc 13 Speedometer gear box
Oil seal A Brake disc bolt
Roller bearing B Front axle nut
Spacer
5-1

CHASSIS

Support the motorcycle by the center stand.
Disconnect the front brake and speedometer cable 1 .
Remove the front axle nut 2 , take off the front wheel 3 .
Do not operate the front brake lever when removing

the front wheel.
Remove the speedometer gearbox assembly 4 .
Remove the front axle spacer and front wheel assembly dust
seal 5 .
Flatten the lock washer, remove the brake disc bolts, take
off the brake disc 6 .
Remove the oil seal 7 on both sides with the special tool.
09913 - 50121: Oil seal remover
5-2

CHASSIS
Remove the bearings 8 on both sides with the special tool,

take off the spacer.
09921-20240: Bearing remover tool
INSPECTION
OIL SEAL
Inspect the oil seal for wear or damage, replace the oil seal if
there are any defects.
FRONT WHEEL AXLE

Using the special tools , check the axle shaft for runout
and replace it if the runout exceeds the limit.
09900-20606 : Dial gauge (1/100)

09900-20701 : Magnetic stand
09900-21304 : V-block (100mm)
Wheel axle runout:
Service limit: 0.25 mm
WHEEL RIM
Make sure that the wheel rim runout does not exceed the
service limit when checked as shown. An excessive amount
of runout is usually due to loose spokes or a bent wheel rim. If
properly tightening the spokes will not correct the runout,
replace the wheel rim.
Wheel rim runout:

Service limit: 2.0 mm
WHEEL BEARING
Inspect the play of the wheel bearings inner race by hand
while fixing it in the wheel hub.
Rotate the inner race by hand to inspect whether abnormal
noise occurs or rotating smoothly.
Replace the bearing if there is something unusual.
5-3

CHASSIS
REASSEMBLY
Reassemble and remount the front wheel in reverse order of
removal. Pay special attention to the following points.
WHEEL BEARING
Apply Super Grease ”A” to bearings before reassembly.
99000-25010: Super grease ”A”

Install left wheel bearing 1 first, then install the spacer 22
and right wheel bearing 3 with the special tool and removed
wheel bearings 4 .
09924-84521: Bearing installer
The sealed cover of the bearing must face outside.
1 Left bearing 3 Right bearing A LH a Clearance

2 Spacer 4 Removed wheel bearing B RH
DUST SEAL
Apply the Super Grease A to the dust seal lips.
Install the new dust seals using the special tool.
99000-25010 : Super grease ”A”

09913-70210 : Bearing installing set (10-75Φ)
5-4

CHASSIS
BRAKE DISC
Make sure that the brake disc is clean and free of any
greasy matter.
Install the brake disc, tighten to the brake disc bolts to the
specified torque.
Front brake disc bolt: 18~28 N•m
Bend the lock washer to the brake disc bolt.
SPEEDOMETER GEAR BOX

Before installing the speedometer gear box, apply Super
Grease A to it, then install it on the wheel.
FRONT AXLE SHAFT

Install the front wheel and front axle , tighten the front axle
nut to the specified torque .
Front axle nut: 36-52 N•m
CAUTION
WARNING
When tightening the front axle, check to be sure that

speedometer gear box is in the position shown.
WARNING
After installing the front wheel, pump the brake lever

until the pistons push the pads correctly.
5-5

CHASSIS
FRONT ABSORBER
CONSTRUCTION
1 O-ring 9 Oil lock piece

2 Plug 10 Oil seal
3 Tube 11 Oil seal stopper ring
ITEM N•m kgf•m
4 Washer 12 Oil seal
A 35-55 3.5-5.5
5 Rebound spring 13 Outer tube B 20-26 2.0-2.6
6 Ring 14 Seal ring
7 Damper rod A Front axle pinch bolt
8 Inner tube B Damper rod bolt
5-6

CHASSIS

Remove the front wheel (refer to page 5-2).
Remove the two bolts and dismount the front caliper 1 .
Remove the four bolts and take off the front fender 2 .
Remove the four handlebar holder clamp bolts, take off the
handle bar 3 , then remove the two front absorber cap bolts.
Remove the decoration plate.

Loosen the lower bracket clamp bolts, put down the left and
right front absorbers.
Remove the cap bolt and draw out the spacer and absorber
spring.
5-7

CHASSIS
Invert the absorber and stroke it several times to remove the

oil.
Remove the damper rod bolt by using the special tools

and hexagon wrench.
11F14 - 010: Front absorber tools
Remove the oil lock piece and damper rod with rebound
spring.
Separate the inner tube from the outer tube.
Remove the stopper ring.
Remove the oil seal by using the special tool.
09913-50121: Oil seal remover
The oil seal removed should be replaced with a new

one.
5-8

CHASSIS
INSPECTION
DAMPER ROD RING
Inspect the damper rod ring for wear and damage.
INNER TUBE AND OUTER TUBE

Inspect the inner tube and outer tube sliding surface for any
scuffing or flaws.
SPRING
Measure the spring free length. If it is shorter than the
service limit, replace it.
Fork spring free length limit: 385.5 mm
* Cleaning: clean the parts with solvent and blow dry.
REMOUNTING
Remounting the front fork in the reverse order of removal, pay
attention to the following points：
DAMPER ROD BOLT
Apply Bond No . 4 and Thread Lock Cement to the damper
rod bolt and tighten the bolt by using the hexagon wrench Thread lock O - ring ( copper )
and special tools.
99000-32040: Thread lock ”1303”
11F14-010: Front absorber tools
Damper rod bolt: 20~26 N•m
Do not reuse the removed O-ring.
5-9

CHASSIS
OIL SEAL
Install the oil seal to the outer tube by using the special
tool as shown.
09940-50112: Absorber oil seal installer
CAUTION
Apply Super Grease lightly on the oil seal lip.
ABSORBER OIL
Pour the specified absorber oil into the inner tube.
Front absorber oil capacity (each leg): 168±3 ml
Absorber oil type: # 32
Hold the front absorber vertical and adjust the absorber oil
level with the special tool.
CAUTION
When adjusting the absorber oil level, compress the
inner tube fully without the absorber spring.
Absorber oil level: 166 mm
09943-74111: Front absorber oil level gauge
FRONT ABSORBER SPRING

Upside
When installing the front fork spring, the close pitch end
should position upside.
Downside
FRONT ABSORBER INNER SCREW PLUG

Install the front absorber inner screw plug and tighten it.
5-10

CHASSIS
REASSEMBLY
Reassemble the front absorbers in the reverser order of
removal. Pay attention to the following points:
Apply a small quantity of absorber oil to the O-ring 1 on
the front absorber.
Absorber oil type: #34
Install the front absorbers to the upper and lower bracket,

tighten the front absorber cap bolts 2 to the specified
torque.
Front absorber cap bolts: 35-55 N•m
Tighten the front absorber lower bracket clamp bolts 3 to

Lower bracket clamp bolt : 25-35 N•m
Install the front caliper, tighten the mounting bolts to the

specified torque.
Lower bracket clamp bolt: 18-28 N•m
Install the front wheel. (Refer to page 5-4)
5-11

CHASSIS
STEERING STEM
CONSTRUCTION
1 Steering stem upper bracket 11 Ball

2 Steering stem lower bracket 12 Upper bearing inner race ITEM N•m kgf•m
3 Upper bracket 13 Lower bearing inner race A 35~55 3.5~5.5
4 Headlight right bracket 14 Ball B 12~20 1.2~2.0
5 Spacer 15 Lower bracket C 25~35 2.5~3.5
6 Dust seal 16 Washer
7 Headlight bracket damper A Steering stem bolt
8 Steering stem nut B Handlebar clamp bolt
9 Dust seal C Lower bracket clamp bolt
10 Upper bearing outer race
5-12

CHASSIS
REMOVAL
Remove the front wheel. (Refer to page 5-2)
Remove the front absorber. (Refer to page 5-6)
Remove the two screws and take off the headlight.
Disconnect the couplers and lead wires.
Remove the lead wires from the headlight housing.

Remove the two bolts and take off the headlight housing.
Remove the two nuts and take off the turn signal lights, right
and left.
Loosen the lower bracket bolts.
Remove the tachometer cable.
5-13

CHASSIS
Remove the two bolts and take off the dashboard assembly.
Remove the ignition switch cover.

Remove the handlebar holder clamp bolts, take off the
handlebar 1 . 1
Remove the front absorber cap bolts and steering stem nut,
take off the upper bracket.
Take off the front absorbers.
Remove the steering stem nut and draw out steering stem.
09940-14911: Steer stem nut wrench
CAUTION
Hold the steering stem by hand to prevent from falling.
Remove the steering stem dust seal and upper bearing outer
race.
5-14

CHASSIS
Remove the upper and lower steel balls.
Number of balls:
Upper: 22 pcs Lower: 18 pcs
Remove the outer race fitted on the steering stem. This can
be down with a chisel.
Draw out the two inner races fitted to the top and bottom
m ends of the head pipe with the special tool.

09941-74910: Steering bearing installer
INSPECTION
Inspect and check the removed parts for the following
abnormalities.
Handlebars distortion.
Handlebars clamp wear.
Race wear and brinelling .
Worn or damaged steel balls.
Distortion of steering stem.
5-15

CHASSIS
REASSEMBLY
Reassemble and remount the steering stem in the reverse
order of removal, and carry out the following steps:
INNER RACES
Press in the upper and lower inner races with a special tool.
09940-34513: Steering race installer
OUTER RACE
Apply grease on the new lower oil seal .
Press in the lower outer race with the special tool.
09941-74910 : Steering bearing installer
STEEL BALL
Apply grease to the upper and lower inner races when
installing the steel balls.
STEERING STEM NUT

Tighten the steering stem nut to 40-50 N•m by using the
special tool.
09941-14911: Steering nut socket wrench

Steer stem bolt: 40~50 N•m
Turn the steering stem right ang left, lock-to-lock, five or

six time to “seat”the ball bearings.
5-16

CHASSIS
Turn back the stem nut by 1/4-1/2 turn.

1/4-1/2 turn back
09910 - 60611: Universal wrench
CAUTION
The adjustment will vary from motorcycle to another.
Tighten the steering stem head bolts to the specified torque.
Steer stem bolt: 35~55 N•m
Install and ighten the front absorber bolts and the brake
caliper bolts. (Refer to page 3-11)
WARNING
After performing the adjustment and installing the

steering stem upper bracket, “rock” the front wheel
assembly forward and backward to ensure that there is
no play and that the procedure was accomplished
correctly. Finally check that the steering stem moves
freely from left to right with its own weight. If play or
stiffness is noticeable, re-adjust the steering stem nut.
HANDLEBAR
Set the handlebar to match its punched mark to the mating
face of the holder.
Secure the each handlebar clamp in such a way that the

clearance A ahead of and behind the handlebar should be
equalized.
Handlebar clamp bolt: 12~20 N•m
5-17

CHASSIS
FRONT BREAK
CONSTRUCTION
1 Brake lever 5 Pad set ITEM N•m kgf•m

2 Piston cup set A Master cylinder clamping bolt A 8-12 0.8-1.2
3 Brake light switch B Brake hose union bolt B 20-25 2.0-2.5
C 6-9 0.6-0.9
4 Brake hose C Air bleeder valve
5-18

CHASSIS
WARNING
The brake system of this motorcycle is filled with a Suzuki brake fluid. Do not use or mix
different types of fuid such as silicone-based and petroleum-based fluid for refilling the
system, otherwise serious damage will be caused.
Do not use any brake fluid taken from old or used or unsealed containers. Never re-use the
brake fluid left over from the last servicing and stored for long periods.
When storing the brake fluid, seal the container completely and keep away from children.
When replenishing brake fluid, take care not to get dust into fluid.
When washing brake components, use new brake fluid. Never use cleaning solvent.
A contaminated brake disc or brake pad reduces braking performance. Discard contaminated
pads and clean the disc with high quality brake cleaner or neutral detergent.
CAUTION
Immediately and completely wipe off any brake fluid contacting any part of the motorcycle. The
brake fluid reacts chemically with paint, plastics and rubber materials, etc., and will damage
them severely.
BRAKE PAD REPLACEMENT

Remove the brake caliper mounting bolts .
Remove the brake pads mounting bolt and brake pads ,

replace the b rake pads.
Replace brake pads as a set; otherwise braking per-

formance will be adversely affected.
Reinstall the new brake pads and the caliper.

Tighten the caliper mounting bolts to the specified torque.
Brake caliper mounting bolts: 18~28 N•m
CAUTION
While installing the brake caliper, push the pistons all
the way into the brake caliper.
5-19

CHASSIS
CALIPER
REMOVAL
Disconnect the brake hose 1 from the caliper catch the
brake fluid in a suitable receptacle.
Remove the caliper mounting bolts 2 and then take off the
caliper.
Never reuse brake fluid left over from the last servicing
or stored for a long period of time.
Do not operate the brake lever with the pads removed.
Remove the brake pads.
Place a rag over the piston to prevent popping up. Force out
the piston by using air gun.
Do not use high pressure air to prevent piston damage.
Remove the piston, piston boot and piston seal.
INSPECTION
MASTER CLIPER
Inspect the master cliper bore for any scratches or other
damage.
5-20

CHASSIS
PISTON
Inspect the piston surface for scratches or other damage.
RUBBER PARTS
Inspect the rubber parts for cracks and damage. If any
defects are found, replace the affected parts.
BRAKE DISC
Visually inspect brake disc for cracks or damage, and
measure brake disc thickness with a micrometer.
09900-20205: Micrometer (0-25 mm)

Brake disc thickness limit: 3.5 mm
Measure the brake disc surface runout with a dial gauge.
09900-20606 : Dial gauge (1/100 mm)

Brake disc runout limit ：0.3 mm
R E A S S E M B LY
Reassemble the cliper in the reverse orders of disassembly
and removal, and also carry out the following steps.
WARNING
Wash the master cylinder components with fresh brake

fluid before reassembly.
Never use cleaning solvent or gasoline to wash them.
Apply brake fluid to the cylinder bore and all internal
parts before inserting into the bore.
5-21

CHASSIS
Tighten the brake hose union bolt to the specific torque.
Brake hose union bolt: 20~25 N•m
Bleed air from the brake fluid circuit after reassembly the
cliper. (Refer to page 2-13)
Brake fluid, if it leaks, will interfere with safe running

and immediately discolor painted surfaces.
Check the brake hoses for cracks and hose joint for
leakage before riding.
MASTER CYLINDER
Place a cloth underneath the union bolt on the master
cylinder to catch spilled drops of brake fluid.
Unscrew the union bolt and disconnect the brake hose from
the master cylinder joint.
Remove two clamp bolts and take off the master cylinder.
Immediately and completely wipe off any brake fluid

contacting any part of the motorcycle. The fluid reacts
chemically with paint, plastics, rubber materials, etc.
and will damage them severely.
Remove two fitting screws, and remove the cap and

diaphragm.
Drain the brake fluid.
Remove the dust seal boot.

Remove the circlip, piston and spring by using the special
tool.
09900-06108: Snap ring pliers
5-22

CHASSIS
INSPECTION
Inspect the master cylinder bore for any scratches or
other damage.
Inspect the piston surface for scratches or other damage.

Inspect the primary cup, secondary cup and dust seal boot
for wear or damage.
REASSEMBLY
Reassemble and remount the master cylinder in the reverse
orders of disassembly and removal, and also carry out the
following steps:
Wash the master cylinder components with fresh brake fluid

before reassembly.
Brake fluid specification: Suzuki brake fluid
When washing the components, use the specified

brake fluid. Never use different types of fluid or Master cylinder
cleaning solvents such as gasoline, kerosine, etc.
Do not wipe the brake fluid off after washing the
components. UP
Apply brake fluid to the cylinder bore and all internal
parts before inserting into the bore.
Handlebar
When remounting the master cylinder on the handlebars,

Cleanrance
tighten the clamp bolts for upside as shown first.
Connect the brake hose, tighten the union bolt to the

specified torque.
Brake hose union bolt: 20~25 N•m
Bleed air from brake system after installing the master

cylinder. (Refer to page 2-12)
5-23

CHASSIS
REAR WHEEL AND REAR BRAKE

CONSTRUCTION
1 Rear axle shaft 12 Brake rod

2 Rear sprocket 13 Brake shoe N•m kgf•m
ITEM
3 Tire 14 Rear break anchor panel A 50-80 5. 0-8.0
4 Roller bearing 15 Brake cam lever B 6 -9 0. 6-0.9
5 Spacer 16 Rear wheel C 18-28 1. 8-2.8
6 Oil seal 17 Roller bearing
7 Roller bearing 18 Spacer
8 Rear sprocket drum retainer A Rear axle nut
9 Rear sprocket drum B Rear brake cam lever nut
10 Damper C Rear sprocket nut
11 Inner tire
5 -24

CHASSIS

Support the motorcycle by the center stand.
Remove the rear brake adjuster nut.
Puff off the cotter pin, remove the torque link nut and bolt.
Remove the rear axle nut.

Loosen the chain adjuster lock nut and adjuster bolt, right
and left.
Draw out the axle shaft and take off the chain from rear
sprocket.
Take off the rear wheel and separate the brake panel from
the wheel.
Flatten the washers and remove the four nuts.

Separate the rear sprocket and mounting drum from the
wheel.
Remove the oil seal by using the special tool.
09913-50121: Oil seal remover
5-25

CHASSIS
Remove the cushion from the wheel.
Remove the right and left side wheel bearings.
It will be easier to remove the left side bearing first.
Take off the brake shoes.
Remove the cam lever nut and bolt.

Pull off the brake cam, washer, O-ring and cam lever.
INSPECTION
Play
WHEEL BEARING

Play
Inspect the wheel bearings for play by hand, Rotate the inner
race by hand to inspect whether abnormal noise occurs and it
rotates smoothly. Replace the bearing if there are any defects.
5-26

CHASSIS
AXLE SHAFT
Using the special tools, check the axle shaft for runout and
replace it if the runout exceeds the limit.
Axle shaft runout limit: 0.25 mm
09900-20606: Dial gauge (1/100)

09900-21304: V - block
SPROCKET
Inspect the sprocket teeth for wear. If they are worn as
illustrated, replace the sprocket and drive chain.
Normal Excessive wear
REAR BREAK DRUM

Measure the brake drum I . D to determine the extent of
wear and, if the limit is exceeded by the wear noted, replace
the drum. The value of this limit is indicated inside the drum.
Break drum I.D. limit：130.7 mm
09900-20103 : Vernier calipers
BRAKE SHOE
Check the brake shoes and decide whether is should be
replaced or not from the thickness of the brake shoe linings.
Brake shoe lining thickness limit: 1.5 mm
09900-20103 : Vernier calipers

WARNING
Replace the brake shoes as a set , otherwise braking

performance will adversely affected.
CUSHION
Inspect the cushion for wear and damage.
5-27

CHASSIS
REASSEMBLY
Reassemble and remount the rear wheel and the rear brake in
the reverse order of disassembly and removal, and also carry
out the following steps.
BEARING
Apply grease to the bearings before installing.

Install the bearings by using the special tool.
First install the bearing for right side.
09913-70210 : Bearing installer
REAR SPROCKET MOUNTING DRUM

Insert the bearing by using the special tool.
09940-53311 : Bearing installer
Apply grease to the mounting drum as shown.
SPROCKET
Tighten the four nuts to specified torque.
Sprocket lock nut: 18~28 N•m
Do not reuse the removed nuts, replace the nuts with

new ones for safe riding.
5-28

CHASSIS
Bend the lock washers.
BRAKE CAM
Apply grease to the brake cam.
99000-25010: Super grease “A”
WARNING
Be careful not to apply too much grease to the brake

cam. If the grease gets on the lining, the brake slippage
will result.
BRAKE CAM LEVER

Install the brake cam lever and tighten the cam lever nut
with specified torque.
Cam lever bolt: 6~9 N•m
5-29

CHASSIS
REAR ABSORBER AND REAR SWING ARM

CONSTRUCTION
A
B
1 Rear swingarm pivot shaft 8 Rear torque link

2 Dust seal 9 Rear swing arm ITEM Nm kgf m
3 Thrust washer 10 Lock washer A 50-80 5.0-8.0
4 Oil seal 11 Bolt B 10-15 1.0-1.5
5 Spacer 12 Chain buffer
6 Spacer A Rear swing arm pivot nut
7 Washer B Rear torque link nut
5-30

CHASSIS

Remove the rear wheel (Refer to page 5-24)
Remove the rear absorber mounting nuts, take off the rear
absorber, right and left..
Remove the chain case mounting screws, take off the chain
case.
Remove the swing arm pivot nut and draw out the shaft .
Remove the swing arm .
Pull off the cotter pin and remove the nut and bolt .
Remove the torque link .
Remove the chain buffer.

Remove the dust seal covers and draw out the spacers.
Draw out the bushings by the special tools.

09930-30102 : Slide shaft
5 -31

CHASSIS
INSPECTION
BUSHING
Inspect the bushing for wear and damage.
SWING ARM PIVOT SHAFT

Using a dial gauge , check the pivot shaft for runout and
replace it if the runout exceeds the limit.
Pivot shaft runout limit: 0.6 mm
09900-20606: Dial gauge (1/100)

09900-21304: V - block
REASSEMBLY
Reassemble and remount the swing arm in the reverse order
of disassembly and removal, and also carry out the following
steps:
Force-fit the bushings into the swing arm by using the
special tool.
09924-84521: Bearing installer set
Apply grease to the spacer and dust seal cover when

installing .
Insert the swing arm pivot shaft from the left side, and
tighten the pivot shaft nut to specified torque.
Tighten the rear absorber nut to the specified torque.

Rear pivot shaft nut: 50~80 N•m
Rear absorber nut: 22~35 N•m
5-32

ELECTRICAL
CONTENTS
STARTER SYSTEM 6-1
IGNITION SYSTEM 6-5
CHARGING SYSTEM 6-7
DASHBOARD 6-11
LIGHTS 6-12
SWITCHES 6-12
BATTERY 6-15 6

ELECTRICAL
STARTER SYSTEM
DESCRIPTION
The starter system is shown in the diagram below: namely, the starter motor, starter relay, starter button, clutch
switch, ignition switch and battery.
Depressing the starter switch(on the right handlebar switch box) energizes the relay, causing the contact points
to close which connects the starter motor to the battery. The motor draws about 70 amperes to start the engine.
Starter relay
Starter button
Fuse
Clutch switch
Battery
Starter motor
TROUBLESHOOTING * Check: One of the front and rear brake light switches is
ON position.
Ignition switch is ON position
Fuse is not blown before the diagnosis.
Starter motor will not run
Check whether to run the starter

motor when connect the starter
Check whether to hear the click motor terminal to the battery
Clicks
noise from the starter relay when terminal directly. (Do not use thin
the starter button is pushed. wire, because a large amount
of current flows.)
Not run
Run
No click
Faulty starter motor
Faulty starter relay
Loose or disconnected starting
(to next page )
motor lead wire
6-1

ELECTRICAL
Measure the starter relay voltage at

the starter relay connectors (between
Y/G and W/B ) when the starter Not voltage Faulty ignition switch
button is pushed. Faulty front brake light switch
Faulty rear brake light switch
Faulty starter button
Voltage measured Poor contact of connector
Open circuit in wiring harness
Check the starter relay

Incorrect Faulty starting relay
(Refer to page 6-9)
Starter motor runs, Open circuit in wiring harness

but does not start engine. Poor contact of connector
Faulty CDI unit
Faulty ignition coil
Faulty generator
Faulty starter clutch
STARTER MOTOR DISASSEMBLY

Remove the starter motor. (Refer to page 3-7)
Disassemble the starter motor as shown.
1 O-ring 4 Amature shaft

2 Housing end(outside) 5 Carbon brush
3 Starter motor body 6 Housing end(inside)
6-2

ELECTRICAL
STARTER MOTOR INSPECTION

CARBON BRUSH
Inspect the carbon brushes for abnormal wear, cracks or
smoothness in the brush holder.
If either carbon brush is defective, replace the brush with a
new one.
Measure the length of the carbon brushes using a vernier
calipers.
If the measurement is less then the service limit, replace the
brush with a new one.
COMMUTATOR
Inspect the commutator for discoloration, abnormal wear.
If the commutator is abnormally worn, replace the armature.
If the commutator surface is discolored, polish it with # 400
sandpaper and wipe it using a clean, dry cloth.
ARMATURE COIL
Inspect for continuity between each segment and between
each segment and the armature shaft using the multi circuit
tester.
If there is no continuity between the segments or there is
continuity between the segments and shaft, replace the
armature with a new one.
09900-25008: Multi circuit tester
Tester knob indication : Continuity test
STARTER MOTOR REASSEMBLY

Fit the depression 1 of the starter motor case to the groove
2 of the housing end (out side).
Align the match mark 3 on the starter motor case with the match
mark 4 on the housing end (inside).
•
STARTER RELAY INSPECTION

Remove the left frame cover.
Remove the starter motor lead wire.
Set the ignition switch to “ON” position, press the starter button
and check for continuity between the positive + and
negative - terminals using the pocket tester. If the starter
relay clicks and continuity is found, the relay is OK.
Tester knob indication : Continuity test

6-3

ELECTRICAL
Measure the relay coil resistance between the terminals using

the multi circuit tester. If the resistance is not within the
specified value, replace the starter relay with a new one.
09900-25008: Pocker tester
Tester knob indication: Resistance (Ω)
Starter relay resistance: 3-6 Ω
6-4

ELECTRICAL
IGNITION SYSTEM
DESCRIPTION
in the capacitor discharged ignition system, the electrical energy generated by the magneto charges the
capacitor. This energy is released in a single surge at the specified ignition timing point, and current flows
through the primary side of the ignition coil. A high voltage current is induced in the secondary windings of the
ignition coil resulting in strong spark between the spark plug cap.
Ignition switch
O/Y
R
O/Y Fuse
Tr i g g e r c o i l
G
Ignitor
Spark plug
W Battery
Ignition coil
Generator
B/W
TROUBLINGSHOOTING
No spark at plug * Check the ignition switch is ” ” position. Inspect
that the fuse is not blown before the diagnosis.
Inspect the battery voltage Less than 12V Recharge the battery or
replace the battery
12V
Check the CDI unit couplers for Looseness Poor contact of couplers
poor contact
Correct
Inspect the ignition circuit Incorrect Faulty ignition switch

Broken wire harness or poor
Correct contact of related circuit
connectors.
Inspect the resistance of trigger coil Incorrect Faulty trigger coil
(Bl/Y and Bl/Y)
Correct
Faulty CDI unit

Faulty ignition coil
Faulty high-tension cord
6-5

ELECTRICAL
IGNITION COIL
Remove the spark plug cap 1 .
Inspect the resistence of ignition coil with the pocket tester.

Tap
09900-25008: Pocket tester
Tester knob indication: X1 Ω range
Ω
KΩ
Primary: 3 . 4-4.6 Ω (tap-tap )
Secondary: 11.05-14.95 k Ω ( tap - plug cap)
Tap
Trigger coil
Measure resistance between lead wires using multi-circuit
tester. If resistance is out of specified values, replace with
new trigger coil.
Tester knob indication: X1 Ω range
Trigger coil resistence: 110 Ω (Bl-G)
Spark plug
(Refer to page 2-7)
IGNITOR UNIT
If the ignition system doesn’t work properly and abnormality
is not detected in the inspections above, replace the ignitor
unit.
6-6

ELECTRICAL
CHARGING SYSTEM
DESCRIPTION
The circuit of the charging system is indicated in the figure, which is composed of an AC generator,
regulator/rectifier unit and battery.
The AC current generated from AC generator is converted by rectifier and is turned into DC current, then is
charges the battery.
Ignition switch
Regulator/rectifier
Load
Battery
A . C generator
TROUBLESHOOTING
Battery runs down quickly
Check accessories which excessively

Installed Remove accessories
waste electric power
Not installed
Inspect battery leak current Leak Short circuit of wiring harness.

Loose or disconnected wires.
No leak Faulty battery.
Inspect charging voltage

Correct Faulty battery.
between battery terminals.
Abnormal driving condition.
Incorrect
Inspect continuity of generator coils No continuity Faulty generator coils or

disconnected lead wires.
Correct
Inspect generator no-load voltage Incorrect Faulty generator. rotor.
Correct
(to next page )
6-7

ELECTRICAL
( Continue the last page )
Inspect regulator/rectifier. Incorrect Faulty regulator/rectifier.
Correct
Inspect wirings, Incorrect Short circuit of wiring harness.

Poor contact of couplers.
Correct
Faulty battery.
Others
Battery overcharge Faulty regulator/rectifier.

Faulty battery.
Poor contact of generator
INSPECTION lead wire coupler.
BATTERY LEAK CURRENT INSPECTION

Remove the left side cover .
Turn the ignition switch to the OFF position.
Disconnect the battery lead wire.
Measure voltage between the battery - terminal and the
specified ground cable terminal. If the reading exceeds
the specified value, then leakage is present.
Battery leakage: Less than 10 µA
Tester knob indication: ( -----, 200µA)

mA
CAUTION
Because the leak current might be large , turn the
tester to high range first when connecting an
ammeter .
Do not turn the ignition switch to the ON position
when measuring current.
GENERATOR COIL INSPECTION
Remove the right side cover.
Disconnect generator coupler 1 .
Measure the resistence between the lead wires, if the
resistence is incorrect, replace the generator coil.

Tester knob indication: Resistance
Generator coil resistance: 0.9 Ω (Y-Y)
6-8

ELECTRICAL
CHARGING OUTPUT INSPECTION

Remove the left side cover.
Start the engine, keep it running at 5 000 r/min, with lighting
switch turned ON and dimmer switch turned HI position.
Measure the DC voltage between the battery terminal and with a
pocket tester. If the tester reads under the specified value,
inspect the generator coil and regulator/rectifier.
CAUTION
When making this test, be sure that the battery is fully-
charged condition.
Battery

Tester knob indication: Voltage
Charging output (DC)
Pocket tester
Standard: 14.6-15.4V at 5 000 r/min
GENERATOR NO-LOAD PERFORMANCE INSPECTION

Disconnect the generator coupler. (Refer to page 6-4)
Start engine and keep it running at 5,000 rpm.
Measure voltage between generator terminal and ground by
using the pocket tester. If the reading is below standard values,
replace with a new generator coil.(Refer to page 3-35)
CAUTION
It is not necessary to remove the engine from the
chassis during the removal the generator coil.

Tester knob indication: Voltage
Generator no-load performance:
75.5-80V/5000 r/min
(When engine is cold)
Regulator/rectifier inspection
If the resistance checked is incorrect, replace the
regulator/rectifier.
6-9

ELECTRICAL
FUEL LEVEL GAUGE

REMOVAL
Remove the fuel tank. (Refer to page 3-2)
Remove the fuel level gauge.
INSPECTION
FUEL LEVEL GAUGE
Remove the fuel lever gauge. (Refer to page 4-3)
Check the resistance of each float position with a pocket
tester.
If the resistance measured is incorrect, replace the fuel A
gauge assembly with a new one. B
The relation between the position of the fuel gauge float
and resistance is shown in the following table.
Float position Resistence
A Full 4-10Ω
B Empty 90-100Ω
TOOL 09900-25008: Pocket tester

Ω
Tester knob indication: x 1 Ω range
CAUTION
When inspecting the gauge resistance, be sure to
disconnect the battery lead wire, or a pocket tester
may be damaged.
FUEL METER
Disconnect fuel level gauge coupler. (Refer to page 4-2)
To test the fuel meter two different checks may be used. The
first, connect a jumper wire between B/W and Y/B wires coming
from the main wiring harness. With the ignition switch turned
ON, the fuel meter should indicted “F”.
The second test will check the accuracy of the meter in the full
and empty positions.
Fuel meter is normal if its pointer indicates the E(empty)
position when the specified resistance is applied to the circuit
and if its pointer indicates the F(full) position when the resistor
is changed to 4-10 ohms.If either one or both indications are
abnormal, replace the fuel meter with a new one. B/W O
Y/B
Resistance 4-10 Ω 90-100 Ω
Float position Full Empty B/W
CAUTION
When inspecting the gauge resistance, be sure to

disconnect the battery lead wire, or a pocket tester
may be damaged.
6-10

ELECTRICAL
DASHBOARD
Remove the dashboard assembly. (Refer to page 5-13)
Disassemble the dashboard assembly as follows.
Upper case Speedometer cable

Dashboard unit Bulb
Lower case Wiring harness
INSPECTION
Using the pocket tester, check the continuity between Dashbaord
lead wires. SP IL
FUEL
TA
If the continuity measured is incorrect, replace the

respective parts. N Gear position light
1 2 3 4 5
Tester knob indication: C ontinuity
CAUTION
Br/R
B/W
W/Y
R/B
G/L
Y/L
YB
BL
Lg
Br
O
Y
When making this test, it is not necessary to remove

the dashboard.
6-11

ELECTRICAL
LIGHTS
HEADLIGHT TURN SIGNAL LIGHT
TAIL LIGHT/BRAKE LIGHT
SWITCHES
Inspect each switch for continuity with the pocket tester .
If any abnormality is found, replace the respective switch
assemblies with new ones.

Test scale: Continuity
IGNITION SWITCH
O R O/Y
OFF
ON ○ ○ ○
6-12

ELECTRICAL
ENGINE STOP SWITCH 1

1
O/B O/W
STARTER SWITCH 2
O/W Y/G
OFF
○ ○
FRONT BRAKE LIGHT SWITCH

B B
OFF
ON ○ ○
DIMMER SWITCH 3 3
Y/W Y W
○ ○
○ ○
TURN SIGNAL LIGHT SWITCH 4

B Sb Lg
○ ○
○ ○
HORN SWITCH 5
B/L B/W
OFF
○ ○
6-13

ELECTRICAL
PASS SWITCH 7
Y O
FREE
PUSH ○ ○
CLUTCH SWITCH 8
B/Y B/W
PUSH ○ ○
REAR BREAK LIGHT SWITCH 9

O W/B
OFF
ON ○ ○
GEAR POSITION INDICATION LIGHT SWITCH 10

Ground L W/Y R/B G/L Y/L Br/R
○ ○
Neutral
○ ○
Low
○ ○
2nd
○ ○
3rd
○ ○
4th
○ ○
Top
6-14

ELECTRICAL
BATTERY Battery
SPECIFICATIONS
Breathe r pipe
TYPE 12N7-4A
Capacity 7 Ah
Standard electrolyte S.G. 1.28 ± 0.01 20 oC
In fitting the battery to the motorcycle, connect the breather

tube to the battery vent.
INITIAL CHARGING
Filling electrolyte
Remove the short sealed tube before filling electrolyte. Fill
battery with electrolyte (dilute sulfuric acid solution with acid
concentration of 35.0% by weight, having a specific gravity of
1.28 at 20 oC/86 oF) up to indicated UPPER LEVEL. Filling
electroltye should be always cooled below 20 oC/86 oF before
filing into battery . Leave battery standing for half an hour
after filing. Add additional electrolyte if necessary.
Charge battery with current as described in the tables shown
below.
Standard Charging current 0.7 A
CHARGING TIME
The charging time for a new battery is determined by the number
of months that have elapsed since the date of manufacture.
Near the end of charging period, adjust the specific gravity of
electrolyte to value specified. After charging, adjust the
electrolyte level to the UPPER LEVEL with DISTILLED WATER.
Months after manufacturing 6-12 Over 12
Necessary charging hours 5 8
Servicing
Visually inspect the surface of the battery container. If any signs
of cracking or electrolyte leakage from the sides of the battery
have occurred, replace the battery with a new one.
If the battery terminals are found to be coated with rust or an
acidic white powdery substance, then this can be cleaned away
with sandpaper.
6-15

ELECTRICAL
Check the electrolyte level and add distilled water, as

necessary, to raise the electrolyte to each cell’s upper level.
Check the battery for proper charge by taking an electrolyte
S.G. reading. If the reading is 1.22 or less, as corrected to
o
20 C, it means that the battery is still in a run-down condition
and needs recharging.
CAUTION
Disconnect the lead first .
BASED ON S.G. READING
Specific gravity
Normal
RECHARGING OPERATION
Recharge
To read the S . G . on the hydrometer, bring the electrolyte
in the hydrometer to eye level and read the graduations on Recharge or Replace
the float scale bordering on the meniscus(curved-up portion
of electroylte) as shown in figure. Temperature
o
Check the reading (as corrected to 20 C) with chart to
determine the recharging time in hours by constant-current
charging at a charging rate of 0.7A.
Be careful not to permit the electrolyte temperature to
o
exceed 45 C, at any time during the recharging operation.
Interrupt the operation, as necessary, to let the electrolyte
cool down. Recharge the battery to the specification. Hydrometer
09900-28403 : Hydrometer
o
Electrolyte specific gravity 1.28 ± 0.01 20 C
CAUTION
Specific gravity at 20 C
Before charging a battery, remove the seal cap from each

cell.
Keep fire and sparks away from a battery being charged.
When removing a battery from the motorcycle, be sure to
remove the terminal first.
CAUTION
o
Charging time (hour)
Constant-voltage charging, otherwise called “quick”

charging, is not recommendable for it could shorten the
life of the battery.
6-16

CONTENTS
TROUBLESHOOTING 7-1
SPECIAL TOOLS 7-7
TIGHTENING TORQUE 7-9
SERVICE DATA 7-11
WIRE AND CABLE ROUTING 7-16
WIRING DIAGRAM 7-18

TROUBLESHOOTING
ENGINE
Complaint Symptom and possible causes Remedy
Engine will not start Compression too low
or is hard to start. 1. Valve clearance out of limit. Adjust.
2. Worn valve guides or poor seating of valves. Repair or replace.
3. Valves mistiming. Adjust.
4. Piston rings excessively worn. Replace.
5. Worn-down cylinder bore. Replace or rebore.
6. Poor seating of spark plug. Retighten.
7. Starting motor cranks but too slowly. Consult "electrical complaints"
Plug not sparking
1. Fouled spark plug. Clean or replace.
2. Wet spark plug. Clean and dry.
3. Defective trigger coil. Replace.
4. Defective ignitor unit. Replace.
5. Defective ignition coil. Replace.
No fuel reaching the carburetor
1. Clogged hole in the fuel tank cap. Clean.
2. Clogged or defective fuel cock. Clean or replace.
3. Defective carburetor float needle valve. Replace.
4. Clogged fuel pipe. Clean or replace.
5. Clogged fuel filter. Clean or replace.
Engine stalls easily 1. Fouled spark plug. Clean.

2. Defective trigger coil. Replace.
3. Defective ignitor unit. Replace.
4. Clogged fuel pipe. Clean.
5. Clogged jets in carburetor. Clean.
6. Valve clearance out of limit. Adjust.
7. Clogged fuel filter. Clean or replace.
Noisy engine Excessive valve chatter

1. Valve clearance too large. Adjust.
2. Weakened of broken valve springs. Replace.
3. Worn down rocker arm or rocker arm shaft. Replace.
Noise appears to come from piston
1. Piston or cylinder worn down. Replace.
2. Combustion chamber fouled with carbon. Clean.
3. Piston pin or piston pin bore worn. Replace.
4. Piston rings or ring groove worn. Replace.
Noise seems to come from clutch
1. Worn splines of countershaft or hub. Replace.
2. Worn teeth of clutch plates. Replace.
3. Distorted clutch plates, driven and drive. Replace.
4. Clutch damper weakened. Replace.
Noise seems to come from crankshaft
1. Worn of burnt bearings. Replace.
2. Big-end bearings worn and burnt. Replace.
3. Thrust clearance too large. Replace.
Noise seems to come from transmission
1. Gears worn of rubbing. Replace.
2. Badly worn splines. Replace.
3. Primary gears worn or rubbing. Replace.
4. Badly worn bearings. Replace.
Slipping clutch. 1. Clutch control out of limit or loss of play. Adjust.

2. Weakened clutch springs. Replace.
3. Worn or distorted pressure plate. Replace.
4. Distorted clutch plates, driven and drive. Replace.
7-1

Dragging clutch. 1.Clutch control out of adjustment or too much play. Adjust.
2.Some clutch springs weakened. Replace.
3.Distorted pressure plate or clutch plates. Replace.
Transmission will 1.Broken gearshift cam. Replace.

not shift. 2.Distorted gearshift forks. Replace.
3.Worn gearshift pawl. Replace.
1.Broken return spring on shift shaft. Replace.
Transmission will Repair.
2.Shift shafts are rubbing or sticky.
not shift back. 3.Distrorted or worn gearshift forks. Replace.
Transmission jumps 1.Worn shifting gears on drive-shaft or counter-shaft. Replace.

out of gear. 2.Distorted or worn gearshift forks. Replace.
3.Weakened stopper pawl spring on gearshift cam. Replace.
4.Worn gearshift pawl. Replace.
1.Valve clearance out of limit. Adjust.

Engine idles poorly. Replace.
2.Poor seating of valves.
3.Defective valve guides. Replace.
4.Worn rocker arm or arm shaft. Replace
5.Defective trigger coil. Replace.
6.Defective ignitor unit. Replace.
7.Spark plug gap too wide. Adjust or replace.
8.Defective ignition coil resulting in weak sparking. Replace.
9.Clogged jets. Clean.
Engine runs poorly 1.Valve springs weakened. Replace.

in high speed range. 2.Valve timing out of limit. Adjust.
3.Worn cams or rocker arms. Replace.
4.Spark plug gap too narrow. Repair.
5.Defective ignition coil. Replace.
6.Clogged air cleaner element. Clean.
7.Clogged fuel hose, resulting in inadequate fuel Clean and prime.
supply to carburetor,
8.Defective trigger coil or ignitor unit. Replace.
Dirty or heavy 1.Too much engine oil in the engine. Check with inspection
exhaust smoke. window.
2.Worn piston rings or cylinder. Replace.
3.Worn valve guides. Replace.
4.Cylinder wall scored or scuffed. Replace.
5.Worn valves stems. Replace.
6.Defective stem seals. Replace.
7.Worn oil rings. Replace.
Engine lacks power. 1. Loss of valve clearance. Adjust.

2. Weakened valve springs. Replace.
3. Valve timing out of limit. Adjust.
4. Worn piston ring or cylinder. Replace.
5. Poor seating of valves. Repair.
6. Fouled spark plug. Clean or replace.
7. Worn rocker arms or its shafts. Replace.
8. Spark plug gap incorrect. Adjust or replace.
9. Clogged jets in carburetor. Clean.
10. Clogged air cleaner element. Clean.
11. Too much engine oil. Drain out excess oil.
12. Suck air intake pipe. Retighten or replace.
Engine overheats. 1. Heavy carbon deposit on piston crown. Clean.

2. Not enough oil in the engine. Pour oil.
3. Defective oil pump or clogged oil circuit. Repair or clean.
4. Air leak from intake pipe. Retighten or replace.
5. Use of incorrect engine oil. Change.
7-2

SERVICE INFORMATION
CARBURETOR
Trouble with 1.Starting jet is clogged. Clean.
starting. 2.Starting pipe is clogged. Clean.
3. Air leakage from a joint between choke and carburetor. Check and retighten.
4. A ir leakage at carburetor joint or vacuum tube joint. Check and retighten.
5 .Starting plunger is not operated properly. Check and adjust.
Idle or low speed 1. Idle jet, idle air jet are clogged or loose. Check and clean.
trouble. 2. Air leakage at carburetor joint, vacuum tube joint or Check and retighten.
choke.
3. Idle outlet or by-pass is clogged. Check and clean.
4. Starting plunger is not fully closed. Check and adjust.
Medium or high- 1. Main jet or main air jet is clogged. Check and clean.
speed trouble. 2. Bubbling pipe is clogged. Check and clean.
3. Throttle valve is not operated properly. Check and adjust.
4. Air filter is clogged. Check and clean.
Overflow and fuel 1. Needle valve is worn or damaged. Replace.

level fluctuations. 2. Needle valve spring is broken. Replace.
3. Float is not working properly. Check and adjust.
4. Foreign matter has adhered to needle valve. Clean.
BRAKES
Poor braking. 1. Not enough brake fluid in the reservoir. Check and refill to level mark.
2. Air trapped in brae fluid circuit. Bleed air out.
3. Pads worn down. Replace.
4. Linings worn down. Replace.
5. Brake disc worn down. Replace.
6. Wheel hub worn down. Replace.
7. Oil adhesion on engaging surface of pads or linings. Clean.
8. Too much play on brake lever. Adjust.
Brake squeaking. 1.Carbon adhesion on pad surface. Repair surface with sandpaper.
2.Tilted pad. Modify pad fitting.
3.Damaged wheel bearing. Replace.
4.Loose front-wheel axle or rear-wheel axle. Tighten to specified torque.
5.Pads or linings worn down. Replace.
6.Foreign material in brake fluid. Replace brake fluid.
7.Clogged return port of master cylinder Disassemble and clean master
cylinder.
Excessive brake 1.Air in hydraulic system. Bleed air out.

lever free stroke. 2.Brake lever cam worn down. Replace brake lever.
3.Insufficient brake fluid. Replenish .
4.Improper quality of brake fluid. Replace with correct fluid.
5.Brake linings or wheel hub worn down. Replace.
Leakage of brake 1.Insufficlent tightening of connection joints. Tighten to specified torque.

fluid. 2.Cracked hose. Replace.
3.Worn piston and/or seal ring. Replace piston and/or cup.
7-3

SERVICE INFORMATION
CHASSIS
Steering feels too 1. Steering stem nut over-tightened. Adjust.
heavy or stiff. 2. Worn bearing or race in steering stem. Replace.
3. Distorted steering stem. Replace.
4. Not enough pressure in tires. Adjust.
Steering oscillation. 1. Loss of balance between right and left front absorbers. Replace.
2. Distorted front absorbers. Repair or replace.
3. Distorted front axle or crooked tire. Replace.
Wobby front wheel. 1.Distorted wheel rim. Replace.

2.Warn-down front wheel bearings. Replace.
3.Defective or incorrect tire. Replace.
4.Loose nut on axle. Retighten.
Front absorbers too 1. Weakened springs. Replace.

soft. 2. Not enough absorber oil. Refill.
Front absorbers too 1. Absorber oil too viscous. Replace.

stiff 2. Too much absorber oil. Remove excess oil.
Noisy front absorbers. 1. Not enough absorbers oil. Refill.

2. Loose nuts on absorbers . Retighten.
Wobbly rear wheel. 1. Distorted wheel rim. Remedy

2. Worn-down rear wheel bearings. Replace.
3. Defective or incorrect tire. Replace.
4. Loose nut on axle. Retighten.
5. Worn swing arm bushings. Replace.
6. Loosen nuts on the rear absorbers. Retighten.
Rear absorbers too 1. Weakened springs. Replace.

soft. 2. Rear absorbers adjuster improperly set. Adjust.
Rear absorbers too 1. Rear suspension adjuster improperly set. Adjust.

stiff. 2. Warn swing arm bushings. Replace.
Noisy rear absorbers. 1. Loose nuts on the rear absorbers . Retighten.

2. Worn swing arm bushings. Replace.
7-4

SERVICE INFORMATION
ELECTRICAL
No spark or 1. Defective ignition coil. Replace.

poor spark. 2. Defective spark plug. Replace.
3. Defective trigger coil or ignitor unit. Replace.
Spark plug soon 1. Mixture too rich. Adjust carburetor.

become fouled 2. Too high idle speed. Adjust carburetor.
with carbon. 3. Incorrect fuel. Change.
4. Dirty element in air cleaner. Clean.
5. Spark plug too cold. Replace by hot type plug.
Spark plug 1.Worn piston rings. Replace.

become fouled 2.Pistons or cylinder worn. Replace.
too soon. 3.Excessive clearance of valve stems in valve guides. Replace.
4.Worn stem oil seals. Replace.
Spark plug 1.Spark plug too hot. Replace by cold type plug.
electrodes 2.The engine overheats. Adjust.
overheat or burn. 3.Defective trigger coil or ignitor unit. Replace.
4.Spark plug loose. Tighten.
5.Mixture too poor. Adjust carburetor.
Generator does 1.Opened or shorted in lead wires, or loose lead Repair or replace or
not charge. connections. retighten.
2.Shorted, grounded or opened generator coils. Replace.
3.Shorted or destroyed regulator/rectifier. Replace.
Generator charge, 1.Lead wires tend to get shorted or opened circuit or Repair or tighten.
but charging rate loosely connected at terminals.
is below the 2.Grounded or opened circuit generator stator. Replace.
specification. 3.Defective regulator/rectifier. Replace.
4.Not enough electrolyte in the battery. Pour distilled water between
the level lines.
5.Defective cell plates in the battery. Replace the battery.
Generator 1.Internal shorted circuit in the battery. Replace the battery.

overcharges. 2.Resistor element in the regulator/rectifier damaged Replace.
or defective. Clean and tighten ground
3.Regulator/rectifier poorly grounded. connection.
Unstable 1.Lead wire insulation frayed due to vibration, resulting Repair or replace.
charging. in intermittent shorted circle.
2.Generator internally shorted circle. Replace.
3.Defective regulator/rectifier. Replace.
Starting button 1.Battery run down. Recharge or replace.
is not effective. 2.Defective switch contacts. Replace.
3.Brusnes not seated properly on commutator in Repair or replace.
starting motor.
4.Defective starting relay. Replace.
7-5

SERVICE INFORMATION
BATTERY
“Sulfation”, acidic 1. Not enough electrolyte. Pour distilled water, if the battery
white powdery has not been damaged and
substance or spots "sulfation" has not advanced
on surface of cell too far, and recharge.
plates. 2.Battery case is cracked. Replace.
3. Charging rate is too low or too high. Replace.
4.Battery has been left in a run-down condition for Replace.
a long time.
5.Contaminated electrolyte (Foreign matter has If "sulfation" has not advanced
enters the battery and become mixed with the too far, try to restore the battery
electrolyte.) by replacing the electrolyte,
recharging it fully and then
adjust the electrolyte S.G.
Battery runs 1. The charging method is not correct. Check the generator,
down quickly. regulator/rectifier and circuit
connections, and make
necessary adjustments to
obtain specified charging
operation.
2. Cell plates have lost much of their active material Replace the battery, and
as result of over-charging. correct the charging system.
3. A shorted circuit condition exists within the battery Replace the battery.
due to excessive accumulation of sediments
caused by the high electrolyte S.G.
4. Electrolyte S.G. is too low. Recharge the battery fully
and adjust electrolyte S.G.
5. Contaminated electrolyte. Replace the electrolyte,
recharge the battery and
adjust the S.G.
6. Battery is too old. Replace the battery.
Reversed battery The battery has been connected the wrong way Replace the battery and be
polarity. round in the system, so that it is being charged in sure to connect the battery
the reverse direction. properly.
Battery discharges 1. Dirty container tap and sides. Clean.

too rapidly. 2. Impurities in the electrolyte or electrolyte S.G. is Change the electrolyte by
too high. consulting the battery
manufacturer ’s directions.
7-6

SPECIAL TOOLS
09900-06107 09900-20103 09900-20202 09900-20203 09900-20205

Snap ring pliers Vernier calipers Micrometer Micrometer Micrometer
(open type) (1/50mm, 300mm) (1/100mm, 25~50mm) (1/100mm, 50~75mm) (1/100mm,0~25mm)
09900-20508 09900-20605 09900-20606

cylinder bore gauge kit Dial calipers Dial meter 09900-20701 09900-20803
(1/100mm,40~80mm) (1/100mm,10~34mm) (1/100mm,10mm) Magnetic bracket Thickness gauge
09900-22302
09900-21304 plastigage 09900-25008 09910-20116 09910-32812
V-block (set) (100mm) (0.051-0.152mm) Pocket tester Conrod holder Crankshaft installer
09913-70210
09910-34510 09910-60611 09913-50121 Bearing installer set 09916-10911
Piston pin puller Universal clamp wrench Oil seal remover Valve seat lapper set
(Φ10-75)
09923- 73210
09915-21110 09920-13120 09921- 20240 Bearing remover 09924-84521
Valve seat reamer set Crankcase separator Bearing remover tool (15-17 mm) Bearing installer set
09930-40113 09940-14911
09930-30102 09930-34980 (11F14-008) Steering stem nut 09940-50112
Slide shaft Rotor remover tool(M33) Sprocket holder socket wrench Absorber oil seal installer
7-7

09941-54911
09940-53311 09941-34513 Bearing outer race 09941-74910
Bearing installer Bearing installer remover Bearing installer
11F14-001 11F14-010 11F14-017 11F14-018 11F14-019

Rotor holder Front absorber tools Valve adjust spring Valve spring tools ”T” valve adjust wrench
11F14-023
Pressure test tool
7-8

TIGHTENING TORQUE
ENGINE
ITEM N•m Kg•m
Cylinder head cover bolt 9-10 0.9-1.0
Cylinder head nut 21-25 2.1-2.5
Camshaft sprocket bolt 10-13 1.0-1.3
Crankcase side bolt 8-12 0.8-1.2
Oil drain plug 20-25 2.0-2.5
Primary drive gear nut 40-60 4.0-6.0
Cltuch sleeve hub nut 30-50 3.0-5.0
Oil inspection plug 25-35 2.5-3.5
Engine sprocket nut 80-100 0.8-10
Muffler clamp bolt 11-15 1.1-1.5
Tensioner bolt 9-14 0.9-1.4
Camshaft sprocket bolt 10-16 1.0-1.6
Generator rotor nut 30-40 3.0-4.0
Starter clutch bolt 8-12 0.8-1.2
Engine mounting bolt Upper 33-39 3.3-3.9
Front 33-39 3.3-3.9
Rear 33-39 3.3-3.9
Engine hanging bolt Upper 22-33 2.2-3.3
Front 22-33 2.2-3.3
7-9

CHASSIS
ITEM N•m Kg • m
Handlebars clamp bolt 12-20 1.2-2.0
Front absorber upper clamp bolt 20-30 2.0-3.0
Steering stem head bolt 35-55 3.5-5.5
Front absorber lower clamp bolt 25-35 2.5-3.5
Front axle nut 36-52 3.6-5.2
Front brake disc bolt 18-28 1.8-2.8
Air bleeder valve 6-9 0.6-0.9
Front brake caliper bolt 18-28 1.8-2.8
Brake hose union bolt 20-25 2.0-2.5
Master cylinder mounting bolt 8-12 0.8-1.2
Swing arm pivot bolt 50-80 5.0-8.0
Rear absorber mounting nut 22-35 2.2-3.5
Rear axle nut 50-80 5.0-8.0
Rear brake cam rocker bolt 6-8 0.6-0.8
Rear torque link nut (Front and Rear) 10-16 1.0-1.6
Rear sprocket nut 18-28 1.8-2.8
Front footrest bolt 34-50 3.4-5.0
TIGHTENING TORQUE CHART

For other bolts and nuts who’s torque is not listed, refer to this chart:
Bolt Diameter Conventional or "4" marked bolt "7" marked bolt
A (mm) N•m Kg • m N•m Kg • m
4 1.5 0.15 2 0.2
5 3 0.3 5 0.5
6 6 0.6 10 1.0
8 13 1.3 23 2.3
10 29 2.9 50 5.0
12 45 4.5 85 8.5
14 65 6.5 135 13.5
16 105 10.5 210 21.0
18 160 16.0 240 24.0
Conventional bolt ”4” marked bolt ”7” marked bolt
7-10

SERVICE DATA
VALVE Unit: mm
ITEM STANDARD LIMIT

Valve diam. IN. 25.5
EX. 22.5
Valve clearance (when cold) IN. 0.04-0.07
EX. 0.13-0.18
Valve guide to valve stem IN. 0.010-0.037

clearance
EX. 0.03-0.057
Valve guide I.D. IN.& EX. 5.000-5.012
Valve stem O.D. IN. 4.975-4.990
EX. 4.955-4.970
Valve stem deflection IN . & EX . 0.35
Valve stem runout IN . & EX . 0.05
Valve head thickness IN . & EX . 0.5
Valve seat width IN . & EX . 0.9-1.1
Valve head radial runout IN . & EX . 0.03
Valve spring Inner 31.24
free length (IN.& EX.) Outer 33.58
CAMSHAFT + CYLINDER HEAD Unit: mm

ITEM STANDARD LIMIT
Cam height IN. 33.65-33.69 33.35
EX. 33.30-33.34 33.00
Camshaft journal oil clearance IN . & EX . 0.021-0.055 0.15
Camshaft journal holder I.D. IN . & EX . 22.012-22.025
Camshaft journal O.D. IN . & EX . 21.970-21.991
Camshaft runout IN . & EX . 0.1
Rocker arm I.D IN . & EX . 12.0-12.018
Rocker arm shaft O . D IN . & EX . 11.977-11.995
Cylinder head distortion 0.05
Cylinder head cover distortion 0.05
7-11

CYLINDER + PISTON + PISTON RING Unit: mm

ITEM STANDARD LIMIT
Compression pressure 1 000-1 400 kPa 800 kPa
Piston to cylinder clearance 0 . 030-0.051 0.12
Cylinder bore 57.010-57.015 57.135
Piston diam. 56.964-56.970 56.844
Measure at 8 mm from the skirt end
Cylinder distortion 0.05
Piston ring free end gap 1st Approx.7.2 5 . 76
2nd Approx.5.8 4 . 64
Piston ring end gap 1st 0.10-0.25 0.7
2nd 0.10-0.25 0.7
Piston ring to groove clearance 1st 0.18

2nd 0.15
Piston ring groove width 1st 1.01-1.03
2nd 1.01-1.03
Oil 2.01-2.03
Piston ring thickness 1st 0.97-0.99
2nd 0.97-0.99
Piston pin bore 14.002-14.008 14.030
Piston pin O . D . 13.996-14.000 13.980
CONROD + CRANKSHAFT Unit: mm

ITEM STANDARD LIMIT
Conrod small end I . D . 14.006-14.014 14.04
Conrod deflection
Conrod big end side clearance 0.10-0.45 1.0
Conrod big end width 15.95-16.0
Crank pin width 52.7-52.9
Crank web to web width 52.9-53.1 0.05
Crank pin O.D. 28.000-28.004
Crankshaft runout 0.05
OIL PUMP
ITEM STANDARD LIMIT
Oil pressure (at 60 °C, 140 °F) 10-30 kPa at 3 000 r/min
7-12

CLUTCH Unit: mm
ITEM STANDARD LIMIT
Clutch cable play 10-15
Drive plate thickness 2.9-3.1 2. 4
Drive plate claw width 11.8-12.0 11.3
Driven plate distortion 0.1
Clutch spring free length 31 29.45
TRANSMISSION + DRIVE CHAIN

ITEM STANDARD LIMIT
Primary reduction ratio 3.470 (59/17)
Final reduction ratio 2.867 (43/15)
Gear ratios Low 3.000 (33/11)

2nd 1.857 (26/14)
3rd 1.368 (26/19)
4th 1.095 (23/21)
Top 0.957 (22/23)
Shift fork to groove clearance 0.10-0.30
Shift fork groove width No.1 & No.2 5.1
No.3 5.5-5.6
Shift fork thickness No.1 & No.2 4.8-4.9
No.3 5.3-5.4
Cuontershaft length
79.8-88.1
(Low to 2nd)
Drive chain Type KMC428HG
Links 116
20 pitch length 259.0 mm
Drive chain slack 10-20 mm
CARBURETOR

Carburetor type BS26 Bubbling jet D Ø3
I.D. No. 054G Main jet E # 110
Needle A 4DH41-2 Idle air screw F 2,5/8 turn out
Needle jet B P -0(390) Idle air jet G # 1.25
Idle jet C # 12.5 Idle 1400 ± 100 r/min
7-13

ELECTRICAL
ITEM SPECIFICATION NOTE
Type NGK CR8E
Spark plug
Gap 0.7 mm-0.8 mm
Primary Terminal - Ground or
4 ± 15 % Ω Terminal - Terminal
Ignition coil resistance
Plug cap - Terminal or
Secondary 13000±20% Ω Plug cap - Plug cap
Trigger Approx.110 Ω Bl-G
Generator coil resistance
Charging Approx.0.9 Ω Y-Y
Generator no-load voltage More than 75.5-80V at 5000 r/min
Regulate voltage 14.6-15.4V at 5 000 r/min
Type designation 12N7-4A
Battery Capacity 12 V7Ah
Standard 1.28±0.01 (20 C )
o
electrolyte S . G .
Fuse 15 A
LIGHT
HI 35 W Dashboard light 2W
Headlight
LO 35 W High beam indicator light 2W
Tail/Brake light 5/21 W Turn signal indicator light 3W
Turn signal light 10 W Gear indication light 2W
Position light 5W
TIRE
ITEM SPECIFICATION LIMIT
Cold inflation tire pressure FRONT 175 kPa(1.75 kgf/cm²)
(Solo riding) REAR 200 kPa(2.00 kgf/cm²)
Cold inflation tire pressure FRONT 175 kPa(1.75 kgf/cm²)
(Dual riding) REAR 225 kPa(2.25 kgf/cm²)
Tire size FRONT 2.75-18 4PR
REAR 3.50-16 4PR
7-14

BRAKE + WHEEL Unit：mm

ITEM STANDARD LIMIT
Rear brake pedal height 20-30
Brake disc thickness Front 3.8-4.2 3.0
Brake disc runout 0.3
Brake fluid type Dot 4
Brake drum I . D . 130.7
Brake lining thickness 1.5
Wheel rim runout Front 2.0
Rear 2.0
Wheel axle runout Front 0.25
Rear 0.25
SUSPENSION Unit：mm
ITEM STANDARD LIMIT
Front fork stroke 130
Front fork spring free length 385.5
Fork fork oil type SUZUKI fork oil #32 or
equivalent fork oil
Front fork oil capacity(each leg) 168±3 ml
Rear suspension spring adjustment 2nd
Swing arm pivot shaft runout 0.6
FUEL +OIL
ITEM STD/SPEC. NOTE
Fuel type Fuel used should be graded 91 octane or higher.
An unleaded fuel is recommended.
Fuel tank Including reserve 10 L
capacity
Reserve 2L
Engine oil type and grade SAE 10W-40, API SF or SG
Engine oil Oil change 850 ml
capacity
Filter change 950 ml
Overhaul 1 300 ml
7-15

WIRE ROUTING
7-16

7-17

WIRING DIAGRAM
DASHBAORD
RIGHT HANDLEBAR SWITCH
SP IL TA
FUEL ENGINE STOP SWITCH IGNITOR REGULATIOR/RECTIFIER
FUEL LEVEL
GEAR POSITION STARTER STOP LIGHT TURN SIGNAL
FRONT BRAKE GAUGE IGNITION COIL
N LIGHT BUTTON SWITCH RELAY
SWITCH
1 2 3 4 5
ON ON
OFF OFF B L
B
B
B/R
B/W
B
B/W
G/L
L
W
O/W
B/W
Y/B
B
O
W/B
O
Sb
Y/G
O/B
O/W
OW
W
W/B
Y
Y
Y
R
B/W
O
BL
Y
YB
B
O
Lg
B/W
Br
W/Y
R/B
G/L
Y/L
Br/R
B/W
Y/B
Y/G
O
O/W
O
W/B
FRONT RIGHT TURN

L
Y
YB
B
O
Lg
B/W
O
W/Y
R/B
G/L
Y/L
Br/R
SIGNAL LIGHT REAR RIGHT TURN
SIGNAL LIGHT
Lg Lg Lg Lg
B/W B/W B/W B/W
HEADLIGHT TAIL LIGHT/BRAKE LIGHT

Y Y O Br
B/W B/W B/W B/W
W W
W/B W/B
POSITION LIGHT
Br O
B/W B/W REAR LEFT TURN

SIGNAL LIGHT
FRONT LEFT TURN
SIGNAL LIGHT B/W B/W
B B B B
7-18
R
Y/G
L/Gr
R
R
R
O
B/W
G/L
FUSE BOX
15A
O/Y
R
B/W
R
L
W/Y
R/B
G/L
Y/L
Br/R
G/L
B/W
L
STARTER RELAY
OFF
B/R
B
ON
L
W/Y
R/B
G/L
Y/L
Br/R
12V 7Ah
G
L
Y
Y
Y
IGNITION SWITCH
N STARTER MOTOR
L/Gr
Lg
Sb
B
B/R
B/W
W
Y
O
Y/W
BATTERY
1
M
2
HORN
3
4
B/Y
Lg
Sb
B
B/L
B/W
W
Y
O
Y/W
5
PUSH GEAR POSITION SWITCH GENERATOR

+
LO
CLUTCH SWITCH HI
L DIMMER SWITCH
PUSH
+
R
PUSH
TURN SIGNAL SWITCH
PASS BUTTON
+
PUSH
HORN BUTTON
LEFT HANDLEBAR SWITCH
JIANG MEN DACHANGJIANG GROUP CO., LTD
Customer service department
1st Ed. DEC, 2014
Printed in China

SUZUKI MOTOR CORPORATION
JIANGMEN DACHANGJIANG GROUP CO., LTD.

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GN125F

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Inexperienced mechanics or mechanics without

DACHANGJIANG GROUP CO.,LTD.

©COPYRIGHT DA CHANGJIANG GROUP CO.,LTD. 2014

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COMPONENT PARTS AND WORK TO BE DONE

Example: Front wheel

1 Front axle shaft

ITEM N•m Kgf•m

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SYMBOL DEFINITION SYMBOL DEFINITION

Torque control required.

Apply oil. Use engine oil unless

Apply or use the absorber oil

Apply SUPER GREASE “A”

Apply MOLY PASTE

Apply sealant “1215”

Apply sealant “1207B”

Apply THREAD LOCK “1342"

Apply THREAD LOCK “1303"

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Indicates a potential hazard that could result in death or injury.

Indicates a potential hazard that could result in motorcycle damage.

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SERIAL NUMBER LOCATIONS

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*The specifications subject to change without notice.

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PERIODIC MAINTENANCE CHART

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Interval Km Initial and Every 5 000 Every 10 000

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To install the battery, reverse the procedure described above.

Make sure that the breather pipe is tightly secured and

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If the air filter is clogged with dust, intake resistance will be

Separate the polyurethane foam element form the element

Fill a washing pan of a proper size with nonflammable clean- B

Do not twist or wring the element because it will tear

If driving under dusty condition , clean the air cleaner

Reassemble the air cleaner in the reverse order of removal.

Make sure the drain plug is fitted correctly after

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Tighten the muffler bolts 1 to the specified torque.

Muffler bolt 1 : 11~15 N•m

CYLINDER HEAD AND CYLINDER NUTS

Tighten four M10 nuts 1 to the specified torque when the

Cylinder head nut: 21~25 N•m

Tighten the cylinder nut 2 and 3 to the specified torque.

Cylinder nut: 8-12 N • m

Excessive valve clearance results in valve noise, insufficient

Valve clearance shoukld be checked when the engine is T

cold. Both the intake and exhaust valve must be