Aprilia RS4 125
Aprilia RS4 125
Aprilia RS4 125
B043126
RS4 125
SERVICE STATION
MANUAL
RS4 125
NOTE Provides key information to make the procedure easier to understand and carry out.
CAUTION Refers to specific procedures to carry out for preventing damages to the vehicle.
WARNING Refers to specific procedures to carry out to prevent injuries to the repairer.
Personal safety Failure to completely observe these instructions will result in serious risk of personal
injury.
Safeguarding the environment Sections marked with this symbol indicate the correct use of the vehicle
to prevent damaging the environment.
Vehicle intactness The incomplete or non-observance of these regulations leads to the risk of serious
damage to the vehicle and sometimes even the invalidity of the guarantee
INDEX OF TOPICS
CHARACTERISTICS CHAR
MAINTENANCE MAIN
ENGINE ENG
SUSPENSIONS SUSP
CHASSIS CHAS
BODYWORK BODYW
PRE-DELIVERY PRE DE
INDEX OF TOPICS
CHARACTERISTICS CHAR
Characteristics RS4 125
Rules
Safety rules
Carbon monoxide
If you need to keep the engine running while working on the vehicle, please ensure that you do so in
an open or very well ventilated area. Never run the engine in an enclosed area. If you do work in an
enclosed area, make sure to use a fume extraction system.
CAUTION
EXHAUST EMISSIONS CONTAIN CARBON MONOXIDE, A POISONOUS GAS WHICH CAN CAUSE
LOSS OF CONSCIOUSNESS AND EVEN DEATH.
Fuel
CAUTION
THE FUEL USED TO POWER INTERNAL COMBUSTION ENGINES IS HIGHLY FLAMMABLE AND
MAY BE EXPLOSIVE UNDER CERTAIN CONDITIONS. IT IS THEREFORE RECOMMENDED TO
CARRY OUT REFUELLING AND MAINTENANCE PROCEDURES IN A VENTILATED AREA WITH
THE ENGINE SWITCHED OFF. DO NOT SMOKE DURING REFUELLING AND NEAR FUEL VA-
POURS, AVOIDING ANY CONTACT WITH NAKED FLAMES, SPARKS OR OTHER SOURCES
WHICH MAY CAUSE THEM TO IGNITE OR EXPLODE.
DO NOT DISPERSE FUEL IN THE ENVIRONMENT.
KEEP OUT OF THE REACH OF CHILDREN
Hot components
The engine and the exhaust system components become very hot and remain hot for some time after
the engine has been switched off. When handling these components, wear insulating gloves or wait
until the engine and the exhaust system have cooled down.
Coolant
The coolant contains ethylene glycol which, under certain conditions, can become flammable.
When it burns, ethylene glycol produces an invisible flame which however can cause burns.
CAUTION
TAKE CARE NOT TO POUR COOLANT ONTO HOT ENGINE OR EXHAUST SYSTEM COMPO-
NENTS; THE FLUID MAY CATCH FIRE AND BURN WITH INVISIBLE FLAMES. WHEN CARRYING
OUT MAINTENANCE OPERATIONS, IT IS ADVISABLE TO WEAR LATEX GLOVES. EVEN
THOUGH IT IS TOXIC, COOLANT HAS A SWEET FLAVOUR WHICH MAKES IT VERY ATTRAC-
TIVE TO ANIMALS. NEVER LEAVE THE COOLANT IN OPEN CONTAINERS IN AREAS ACCES-
SIBLE TO ANIMALS AS THEY MAY DRINK IT.
CHAR - 6
RS4 125 Characteristics
BRAKE AND CLUTCH FLUIDS CAN DAMAGE THE PLASTIC OR RUBBER PAINTED SURFACES.
WHEN SERVICING THE BRAKING SYSTEM OR THE CLUTCH SYSTEM, PROTECT THESE COM-
PONENTS WITH A CLEAN CLOTH. ALWAYS WEAR PROTECTIVE GOGGLES WHEN SERVICING
THESE SYSTEMS. BRAKE AND CLUTCH FLUIDS ARE EXTREMELY HARMFUL FOR YOUR
EYES. IN THE EVENT OF ACCIDENTAL CONTACT WITH THE EYES, RINSE THEM IMMEDIATELY
WITH ABUNDANT COLD, CLEAN WATER AND SEEK MEDICAL ADVICE.
KEEP OUT OF THE REACH OF CHILDREN
Battery electrolyte and hydrogen gas
CAUTION
Maintenance rules
GENERAL PRECAUTIONS AND INFORMATION
When repairing, dismantling and reassembling the vehicle, follow the recommendations given below
carefully.
CHAR - 7
Characteristics RS4 125
• Before dismantling components, remove dirt, mud, dust and foreign bodies from the vehicle.
Use the special tools designed for this bike, as required.
COMPONENTS REMOVAL
• Do not loosen and/or tighten screws and nuts using pliers or any other tools than the specific
wrench.
• Mark positions on all connection joints (pipes, cables etc.) before separating them, and
identify them with distinctive symbols.
• Each component needs to be clearly marked to enable identification during reassembly.
• Clean and wash the dismantled components carefully using a low-flammability detergent.
• Keep mated parts together since they have "adjusted" to each other due to normal wear.
• Some components must be used together or replaced completely.
• Keep away from heat sources.
REASSEMBLING COMPONENTS
CAUTION
BEARINGS MUST ROTATE FREELY, WITHOUT JAMMING AND/OR NOISE, OTHERWISE, THEY
NEED TO BE REPLACED.
• Only use ORIGINAL Aprilia SPARE PARTS.
• Comply with lubricant and consumables use guidelines.
• Lubricate parts (whenever possible) before reassembling them.
• When tightening nuts and screws, start either from the components with the largest diameter
or from the innermost components, proceeding diagonally. Tighten nuts and screws in suc-
cessive steps before applying the tightening torque.
• Always replace self-locking nuts, washers, sealing rings, circlips, O-rings (OR), cotter pins
and screws with new parts if the thread is damaged.
• When assembling the bearings, make sure to lubricate them well.
• Check that each component is assembled correctly.
• After a repair or routine maintenance, carry out pre-ride checks and test the vehicle on
private grounds or in an area with low traffic.
• Clean all mating surfaces, oil seal rims and gaskets before refitting. Smear a thin layer of
lithium-based grease on the oil seal rims. Reassemble oil seals and bearings with the brand
or batch number facing outward (visible side).
ELECTRICAL CONNECTORS
Electric connectors must be disconnected as described below; failure to comply with this procedure
causes irreparable damage to both the connector and the wiring harness:
Press the relative safety clips, if applicable.
• Grip the two connectors and disconnect them by pulling them in opposite directions.
CHAR - 8
RS4 125 Characteristics
• If any signs of dirt, rust, moisture, etc. are noted, clean the inside of the connector carefully
with a jet of compressed air.
• Ensure that the cables are correctly fastened to the internal connector terminals.
• Then connect the two connectors, ensuring that they couple correctly (if fitted with clips, you
will hear them "click" into place).
CAUTION
DO NOT DISCONNECT CONNECTORS BY PULLING THE CABLES.
NOTE
THE TWO CONNECTORS CAN ONLY BE CONNECTED IN ONE DIRECTION: CONNECT THEM
THE RIGHT WAY ROUND.
TIGHTENING TORQUES
CAUTION
REMEMBER THAT THE TIGHTENING TORQUES FOR ALL FASTENING ELEMENTS ON WHEELS,
BRAKES, WHEEL AXLES AND ANY OTHER SUSPENSION COMPONENTS PLAY A KEY ROLE
IN ENSURING VEHICLE SAFETY AND MUST COMPLY WITH SPECIFIED VALUES. CHECK THE
TIGHTENING TORQUES OF FASTENING ELEMENTS ON A REGULAR BASIS AND ALWAYS USE
A TORQUE WRENCH TO REASSEMBLE THESE COMPONENTS. FAILURE TO COMPLY WITH
THESE RECOMMENDATIONS MAY CAUSE ONE OF THESE COMPONENTS TO LOOSEN OR
EVEN DETACH, CAUSING A WHEEL TO LOCK OR COMPROMISING VEHICLE HANDLING. THIS
MAY LEAD TO FALLS, WITH THE RISK OF SERIOUS INJURY OR DEATH.
Running-in
Running the engine in correctly is essential for ensuring engine longevity and functionality. Twisty roads
and gradients are ideal for running in the engine, brakes and suspension effectively. Vary your riding
speed during the running in period. This ensures that components operate in "loaded" conditions and
then "unloaded" conditions, allowing the engine components to cool.
CAUTION
THE FULL PERFORMANCE OF THE VEHICLE IS ONLY AVAILABLE AFTER THE SERVICE AT
THE END OF THE RUNNING IN PERIOD.
Follow the guidelines detailed below:
• Do not fully open the throttle grip abruptly at low engine speeds, either during or after the
running in period.
• During the first 100 Km (62 miles) use the brakes gently, avoiding sudden or prolonged
braking. That is to permit the adequate adjustment of the pad friction material to the brake
discs.
Vehicle identification
CAUTION
CHAR - 9
Characteristics RS4 125
Chassis number
The chassis number is stamped on the right hand
side of the headstock.
This number consists of numbers and letters, as in
the example shown below.
ZD4TW0000YSXXXXXX
KEY:
ZD4: WMI (World manufacturer identifier) code;
TW: model;
000: version variation;
0: free digit
Y year of manufacture
S: production plant (H= Martorelles (Spain); S=
Scorzè (Italy); 4= Zongshen (China); 5= Ponte-
dera (Italy); M= Mandello del Lario (Italy)
XXXXXX: serial number (6 digits);
CHASSIS NUMBER
The chassis number is stamped on the right hand
side of the headstock.
DIMENSIONS
Specification Desc./Quantity
Maximum length 1,953 mm (76.89 in)
Maximum width (with mirrors) 740 mm (29.13 in)
Maximum height to the windshield 1,138 mm (44.80 in)
Saddle height 837 mm (32.95 in)
Height passenger saddle 978 mm (38.50 in)
Height handlebar 840 mm (33.07 in)
Minimum ground clearance 137 mm (5.39 in)
Wheelbase 1,350 mm (53.15 in)
Kerb weight 140 kg (308.64 lb)
Weight (without fuel) 135.8 kg (299.39 lb)
Engine
ENGINE
Specification Desc./Quantity
Engine type Single cylinder 4 stroke
Engine capacity (125) 124.2 cm³ (7.58 cu.in)
Bore x Stroke (58 x 47) mm; (2.28 x 1.85) in
Compression ratio 12.6 +/- 0.5 : 1
Electric starter
Idle speed 1900 +/- 100 rpm
Clutch multiple-disk, oil-bathed clutch with hand control on the left side
of the handlebar.
CHAR - 10
RS4 125 Characteristics
Specification Desc./Quantity
Cooling Coolant
Valve clearance at intake 0.15 mm (0.0059 in)
Exhaust valve clearance 0,25 mm (0.0098 in)
GEAR
Specification Desc./Quantity
Type mechanic, 6-speed gearbox with pedal on the engine left side
which operates the selector with fork and distribution drum.
Transmission
GEAR RATIOS
Specification Desc./Quantity
1st gear ratio 11 / 33 = 1 : 3,000
2nd gear ratio 15 / 30 = 1 : 2.000
3rd gear ratio 18 / 27 = 1 : 1.500
4th gear ratio 20 / 24 = 1 : 1.200
5th gear ratio 25 / 27 = 1 : 1,080
6th gear ratio 23 / 22 = 1 : 0.956
Final drive gear ratio 13 / 60
Capacities
CAPACITY
Specification Desc./Quantity
Fuel tank 14.5+/-0.5 l (3.19+/-0.11 UK gal; 3.83 +/-0.13 US gal)
Fuel tank reserve 3.3 l (3.19+/-0.72 UK gal; 0.87 USgal)
Engine oil 1,200 cm³ (73.23 cu.in)
Seats 2
Coolant 0.78 l (0.171 UKgal; 0.206 US gal)
Coolant reserve 0.23 l (0.0506 UKgal; 0.0607 US gal)
Vehicle maximum load (rider + passenger + luggage) 180 kg (396.83 lb)
Vehicle load without passenger (rider + luggage) 105 kg (231.48 lb)
Electrical system
IGNITION
Specification Desc./Quantity
Type CDI
SPARK PLUG
Specification Desc./Quantity
Spark plug NGK CR9 EB Alternatively Champion RG4HC
Electrode gap 0.5 mm (0.020 in)
ELECTRICAL SYSTEM
Specification Desc./Quantity
Battery 12V - 6 Ah
Fuses 30A, 20A, 15A, 7.5A
Alternator 13 V - 235 W
BULBS
Specification Desc./Quantity
Low beam light - 12 V - 35 W H4
High beam light H11 - 12V - 55W
CHAR - 11
Characteristics RS4 125
Specification Desc./Quantity
2 daylight running lights 12V - 5W
Turn indicator light Micro bulb
Rpm indicator lighting 12 V - LED
Rear daylight running light/stop light LED
License plate lamp (where provided) 12V - 5W
WARNING LIGHTS
Specification Desc./Quantity
Instrument panel warning lights LED
CHASSIS
Specification Desc./Quantity
Chassis type Aluminium dual beam
Trail 93.6 mm (3.68 in)
SUSPENSIONS
Specification Desc./Quantity
Front Hydraulic action telescopic fork with upside-down stems
Front wheel travel 110 mm (4.33 in)
Rear single hydraulic shock absorber
Rear wheel travel 122 mm (4.80 in)
Brakes
BRAKES
Specification Desc./Quantity
Front Ø 300 mm (11.81 in) disc brake
Rear Ø 218 mm (8.58 in) disc brake
WHEEL RIMS
Specification Desc./Quantity
Type made of light alloy
Front 2.75 x 17''
Rear 3.50 x 17''
TYRES
Specification Desc./Quantity
Front - size (where applicable for approvals) 100 / 80 17'' 52H or alternatively 110 / 70 17" 54H
Front inflation pressure - rider only 1.7 bar (170 kPa) (24.66 PSI)
Front inflation pressure - rider + passenger 1.8 bar (180 kPa) (26.11 PSI)
Rear - size (where applicable for approvals) 130 / 70 17'' 62H or alternatively 150 / 60 17" 66H
Rear inflation pressure - rider only 1.8 bar (180 kPa) (26.11 PSI)
Rear inflation pressure - rider + passenger 1.9 bar (190 kPa) (27.56 PSI)
CHAR - 12
RS4 125 Characteristics
Supply
FUEL SYSTEM
Specification Desc./Quantity
Fuel premium unleaded petrol as per DIN 51 607, minimum octane
rating of 95 (NORM) and 85 (NOMM).
Tightening Torques
Chassis
Front side
FRONT LIGHTS
pos. Description Type Quantity Torque Notes
1 Headlamp fixing screw M5x14 4 2.5 Nm (1.84 lbf ft) -
2 Self-tapping screw M5 1 1.5 Nm (1.11 lbf ft) -
3 Turn indicator fixing screw M5 2 1.5 Nm (1.11 lbf ft) -
CHAR - 13
Characteristics RS4 125
STEERING
pos. Description Type Quantity Torque Notes
1 Upper yoke fastening to sleeve M8 2 25 Nm (18.43 lbf ft) -
2 Steering retainer nut M20 1 48 Nm (35.40 lbf ft) -
CHAR - 14
RS4 125 Characteristics
FRONT SUSPENSION
pos. Description Type Quantity Torque Notes
1 Screws fastening lower yoke to M8 2x2 25 Nm (8.43 lbf ft) -
sleeve
FRONT WHEEL
pos. Description Type Quantity Torque Notes
1 Front wheel spindle nut M14 1 78 Nm (8.85 lbf ft) -
2 Front disc fixing screw M6x20 6 12 Nm (8.85 lbf ft) -
CHAR - 15
Characteristics RS4 125
CHAR - 16
RS4 125 Characteristics
AIR DEFLECTORS
pos. Description Type Quantity Torque Notes
1 Radiator frame screw M5x16 1 2 Nm (1.47 lbf ft) Max 2.5 N (1.84 lbf
ft)
2 Front fixing screw Self-t. 3.9 2 1 Nm (0.74 lbf ft) -
3 TCEI screw M5x20 2 2 Nm (1.47 lbf ft) Max 2.5 N (1.84 lbf
ft)
4 Flanged TBEI screw M5x16 2 3 Nm (2.21 lbf ft) -
CHAR - 17
Characteristics RS4 125
INSTRUMENT PANEL
pos. Description Type Quantity Torque Notes
1 Self-tapping screw M5x4 3 2.5 Nm (1.84 lbf ft) -
2 Instrument panel fixing screw M5x20 6 2 Nm (1.47 lbf ft) -
CHAR - 18
RS4 125 Characteristics
FRONT CALLIPER
pos. Description Type Quantity Torque Notes
1 Front calliper fixing screw M10x60 2 50 Nm (36.87 lbf ft) -
CHAR - 19
Characteristics RS4 125
CLUTCH CONTROL
pos. Description Type Quantity Torque Notes
1 Throttle cable ring fixing screw M6x16 1 6 Nm (4.42 lbf ft) -
2 Throttle control fixing screw M6x20 1 10 Nm (7.37 lbf ft) -
WINDSHIELD
pos. Description Type Quantity Torque Notes
1 Rear view mirror fixing screw Self-t. 3.9 4 0.4 Nm (0.29 lbf ft) -
CHAR - 20
RS4 125 Characteristics
Central part
CHASSIS
pos. Description Type Quantity Torque Notes
1 Support coil fixing screw M8 2 20 Nm (14.75 lbf ft) -
2 TCEI screw M8 2 25 Nm (18.43 lbf ft) -
3 TCEI screw M10x45 4 50 Nm (36.88 lbf ft) -
4 TE screw M8x40 2 25 Nm (18.43 lbf ft) -
5 TE screw M6x16 2 12 Nm (8.85 lbf ft) Loctite 243
6 Right and left engine mount M10x16 2 38 Nm (28.02 lbf ft) Loctite 243
CHAR - 21
Characteristics RS4 125
REAR BODYWORK
pos. Description Type Quantity Torque Notes
1 Side fairing to chassis fixing screw M4x14 2 - -
2 Plastic panel fixing screw M5x12 6 3 Nm (2.21 lbf ft) -
3 Side fairing to chassis fixing screw M5x9 2 3 Nm (2.21 lbf ft) -
4 Side fairing to chassis fixing screw M5x9 2 3 Nm (2.21 lbf ft) -
5 SWP Screw M5x20 2 2 Nm (1.47 lbf ft) -
6 Self-tapping screw 3.9x10 4 0.4 Nm (0.29 lbf ft) -
7 Self-tapping screw M5x14 2 1.5 Nm (1.11 lbf ft) -
8 TBEI screw M5x12 1 3 Nm (2.21 lbf ft) -
CHAR - 22
RS4 125 Characteristics
TANK
pos. Description Type Quantity Torque Notes
1 Rear tank fixing screw M8x40 1+1 25 Nm (18.44 lbf ft) -
2 Front tank fixing screw M6x35 1 10 Nm (7.37 lbf ft) -
3 Fastener screw M5x9 4 3 Nm (2.21 lbf ft) -
4 Tank cover fixing screw M5x9 4 3 Nm (2.21 lbf ft) -
CHAR - 23
Characteristics RS4 125
SIDE FAIRINGS
pos. Description Type Quantity Torque Notes
1 Side fairing fixing screw M5x9 6 1.7 Nm (1.25 lbf ft) Max 2 Nm (1.47 lbf
ft)
EXHAUST
pos. Description Type Quantity Torque Notes
1 Drainage retainer M6x20 2 10 Nm (7.37 lbf ft) -
2 Footrest retainer M8x40 1 25 Nm (18.43 lbf ft) -
CHAR - 24
RS4 125 Characteristics
RADIATOR
pos. Description Type Quantity Torque Notes
1 Radiator retainer M6x25 2 10 Nm (7.37 lbf ft) -
2 Expansion tank support fixing screw M6x20 1 3.5-4 Nm (2.58-2.95 lbf -
ft)
CHAR - 25
Characteristics RS4 125
FOOTRESTS
pos. Description Type Quantity Torque Notes
1 Rider footrest support fixing screw M8x25 1+1 25 Nm (18.43 lbf ft) Loctite 243
2 Footrest protection fixing screw M5x12 2+2 5 Nm (3.69 lbf ft) -
3 Passenger footrest fixing screw M8x40 4 20 Nm (14.75 lbf ft) -
4 Rider pedal retainer M8x26 2 25 Nm (18.44 lbf ft) -
CHAR - 26
RS4 125 Characteristics
CENTRAL BODYWORK
pos. Description Type Quantity Torque Notes
1 Fairing upper fixing screw M5x9 6 3 Nm (2.21 lbf ft) -
2 Fairing lower fixing screw M4x14 2 - -
STAND
pos. Description Type Quantity Torque Notes
1 Thin nut M10x1.25 1 10 Nm (7.38 lb ft) -
CHAR - 27
Characteristics RS4 125
LOCKS
pos. Description Type Quantity Torque Notes
1 Fuel tank cap retainer M5x16 3 3 Nm (2.21 lb ft) -
2 Fuel tank cap retainer M5x30 2 3 Nm (2.21 lb ft) -
3 Saddle lock retainer M6x30 2 6 Nm (4.42 lb ft) -
4 Steering lock retainer M8x20 2 6.5 Nm (4.79 lb ft) -
CHAR - 28
RS4 125 Characteristics
Back side
REAR SUSPENSION
pos. Description Type Quantity Torque Notes
1 Upper retainer M12 1 58 Nm (42.78 lbf ft) -
2 Lower retainer M12 1 58 Nm (42.78 lbf ft) Loctite 243
CHAR - 29
Characteristics RS4 125
SWINGARM
pos. Description Type Quantity Torque Notes
1 Swingarm to chassis adjustment nut M25x1.5 1 15 Nm (11.06 lbf ft) -
2 Swingarm pin nut M14 1 78 Nm (57.52 lbf ft) -
3 Chainguard fixing screw M 4.8x13 4 1 Nm (0.74 lbf ft) -
4 Chainguard fixing screw Self-tap. 2 - -
REAR WHEEL
pos. Description Type Quantity Torque Notes
1 Rear wheel axle nut M14 2 78 Nm (57.53 lbf ft) -
2 Rear disc fixing screw M6x20 6 12 Nm (8.85 lbf ft) -
3 Sprocket fixing screw TEF M8 6 25 Nm (18.44 lbf ft) -
4 Chain tensor fixing screw M8 2 12 Nm (8.85 lbf ft) Loctite 243
CHAR - 30
RS4 125 Characteristics
REAR LIGHTS
pos. Description Type Quantity Torque Notes
1 Turn indicator retainer M5 2 3 Nm (2.21 lbf ft) -
2 Turn indicator cover retainer - 2+2 0.3 Nm (0.22 lbf ft) -
CHAR - 31
Characteristics RS4 125
REAR MUDGUARD
pos. Description Type Quantity Torque Notes
1 Rear mudguard to swingarm fixing Self-tap. 4 3 Nm (2.21 lbf ft) Max 4.5 Nm (3.31
screw lbf ft)
Engine
CRANKSHAFT
pos. Description Type Quantity Torque Notes
1 Countershaft gear retainer nut M10 1 35 - 45 Nm (25.81 - -
33.19 lbf ft)
CHAR - 32
RS4 125 Characteristics
CYLINDER - PISTON
pos. Description Type Quantity Torque Notes
1 Chain tensioner screw M8 1 6 Nm (4.43 lbf ft) -
THROTTLE BODY
pos. Description Type Quantity Torque Notes
1 Intake manifold fixing screw M6x20 3 10 Nm (7.38 lbf ft) -
CHAR - 33
Characteristics RS4 125
CLUTCH COVER
pos. Description Type Quantity Torque Notes
1 Clutch cover fixing screw M6x35 10 11 - 13 Nm (8.11 - 9.58 -
lbf ft)
2 Oil filter cover M56x1.5 1 24 - 26 Nm (17.70 - -
19.17lbf ft)
3 Oil pressure sensor M10 1 12 - 14 Nm (8.85 - 10.32 -
lbf ft)
CHAR - 34
RS4 125 Characteristics
HEAD COVER
pos. Description Type Quantity Torque Notes
1 Spark plug M10 1 12 - 14 Nm (8.85 - 10.32 -
lbf ft)
2 Head cover fixing screw M6 4 10 - 12 Nm (7.38 - 8.85 -
lbf ft)
FLYWHEEL COVER
pos. Description Type Quantity Torque Notes
1 Flywheel cover fastener screw M6 10 11 - 13 Nm (8.11 - 9.58 -
lbf ft)
2 Timing control cover M18 2 3.5 - 4.5 Nm (2.58 - 3.31 -
lbf ft)
3 Oil dipstick M12x1.5 1 4 - 6 Nm (2.95 - 4.42 lbf -
ft)
CHAR - 35
Characteristics RS4 125
TIMING SYSTEM
pos. Description Type Quantity Torque Notes
1 Chain tensioner slider fulcrum fixing M6x16 1 10 Nm (7.38 lbf ft) Loctite 243
screw
2 Transmission timing gear fixing M8x40 1 27 Nm (19.91 lbf ft) Loctite 243
screw
CHAR - 36
RS4 125 Characteristics
CLUTCH
pos. Description Type Quantity Torque Notes
1 Clutch spring screw M5 5 3.5 - 4.5 Nm (2.58 - 3.31 -
lbf ft)
2 Clutch housing retainer nut M12 1 35 - 45 Nm (25.81 - -
33.19 lbf ft)
STARTER MOTOR
pos. Description Type Quantity Torque Notes
1 Starter motor fixing screw M6x25 2 11 - 13 Nm (8.11 - 9.58 -
lbf ft)
CHAR - 37
Characteristics RS4 125
WATER PUMP
pos. Description Type Quantity Torque Notes
1 Water pump fixing screw M5 3 5 - 6 Nm (3.68 - 4.42 lbf -
ft)
OIL PUMP
pos. Description Type Quantity Torque Notes
1 Oil pump fixing screw M6x25 3 10 Nm (7.38 lbf ft) Loctite 243
CHAR - 38
RS4 125 Characteristics
GEAR SELECTOR
pos. Description Type Quantity Torque Notes
1 Selector spider screw M5 1 3.5 - 4.5 Nm (2.58 - 3.31 -
lbf ft)
2 Engaging lever screw M6 1 8 - 10 Nm (5.90 - 7.38 lbf -
ft)
CHAR - 39
Characteristics RS4 125
ENGINE CRANKCASE
pos. Description Type Quantity Torque Notes
1 Crankcase halves union M6 12 11 - 13 Nm (8.11 - 9.58 -
lbf ft)
HEAD - VALVES
pos. Description Type Quantity Torque Notes
1 Head fastener screw, chain side M6x130 2 11 Nm (8.11 lbf ft) -
2 Exhaust side fixing stud bolt M8x40 2 12 Nm (8.85 lbf ft) -
3 Camshaft support fixing screw M6x40 8 10 Nm (7.38 lbf ft) -
4 Head fixing screw M8x166 4 25 Nm + 90° (18.44 lbf ft -
+ 90°)
5 Thermostat cover fixing screw M6x20 2 10 Nm (7.38 lbf ft) -
CHAR - 40
RS4 125 Characteristics
IGNITION UNIT
pos. Description Type Quantity Torque Notes
1 Flywheel rotor fixing screw M14x1.5 1 83 - 90 Nm (61.21 - -
66.38 lb ft)
LEVERS
pos. Description Type Quantity Torque Note
1 Pinion retainer nut M12x1.25 1 30 Nm (22.12 lb ft) Loctite 270
CHAR - 41
Characteristics RS4 125
Characteristic
Rod small end
Maximum diameter: 15.023 mm (0.591 in)
Standard diameter: 15.010 - 15.018 mm (0.5910 - 0.5912 in)
CRANKSHAFT DIAMETER
Specification Desc./Quantity
Class 1 MIN 32.480 mm (1.2787 in)
MAX 32.485 mm (1.2789 in)
Class 2 MIN 32.485 mm (1.2789 in)
MAX 32.490 mm (1.2791 in)
BUSHING THICKNESS
Specification Desc./Quantity
Red MIN 2.005 mm (0.0789 in)
MAX 2.010 mm (0.0791 in)
Blue MIN 2.010 mm (0.0791 in)
MAX 2.015 mm (0.0793 in)
CHAR - 42
RS4 125 Characteristics
CHAR - 43
INDEX OF TOPICS
SPECIFIC TOOLS
Stores code Description
AP8140266 Dial gauge mounting
S-TOOLS - 45
Special tools RS4 125
S-TOOLS - 46
RS4 125 Special tools
020357Y 32 x 35 mm adaptor
S-TOOLS - 47
Special tools RS4 125
020483Y 30 mm guide
020364Y 25 mm Adaptor
S-TOOLS - 48
INDEX OF TOPICS
MAINTENANCE MAIN
Maintenance RS4 125
Maintenance chart
Correct maintenance is fundamental for ensuring the longevity of your vehicle and maintaining optimum
function and performance.
To this end, Aprilia offers a set of checks and maintenance services (at the owner's expense), that are
summarised in the table shown on the following page. Any minor faults must be reported without delay
to an Authorised Aprilia Dealer or Sub-Dealer without waiting until the next scheduled service to
solve it.
All scheduled services must be carried out at the specified intervals and mileage, as soon as the pre-
determined mileage is reached. Carrying out scheduled services on time is essential for the validity of
your warranty. For further information regarding Warranty procedures and ''Scheduled Maintenance'',
please refer to the ''Warranty Booklet''.
NOTE
CARRY OUT MAINTENANCE OPERATIONS AT HALF THE INTERVALS SPECIFIED IF THE VE-
HICLE IS USED IN PARTICULAR RAINY OR DUSTY CONDITIONS, OFF ROAD OR FOR TRACK
USE.
I: INSPECT AND CLEAN, ADJUST, LUBRICATE OR REPLACE IF NECESSARY
C: CLEAN, R: REPLACE, A: ADJUST, L: LUBRICATE
(1) Grease every 500 Km (310 mi) and before each use in severe conditions.
(2) Replace every 2 years or 18000 Km (11185 mi).
(3) Replace every four years.
(4) Check every month.
(5) Check at each starter (brakes, direction, clutch, suspension, engine, lights, warning lights).
(6) Replace when reaching the first of the following two options: 36,000 km (22,369 mi) or 48 months.
MAIN - 50
RS4 125 Maintenance
km(mi)x1000 1 6 12 18 24 30 36 42 48
(0.621) (3.728) (7.456) (1.184) (14.913) (18.641) (22.369) (26.097) (29.826)
Callipers and brake disc I I I I I I I I
Tyres I I I I I I I I I
Tyres pressure (4) I I I I I I I I I
Radiator - External cleaning C C C C
Valve adjustment I I I I
Odometer gear I I
Wheels (4) I I I I I I I I I
Discharge I I I I
Tightening screws I I I I
Front suspension: oil (6) R
Warning lights I I I I I I I I I
Fuel and oil + filters pipes I I R I I R I I R
(3)
Brakes pipes I I I I I I I I
Engine support screws I I I I
Spark plug
SPARK PLUG
Specification Desc./Quantity
Spark plug NGK CR9 EB Alternatively Champion RG4HC
Electrode gap 0.5 mm (0.020 in)
MAIN - 51
Maintenance RS4 125
Engine oil
Check
MAIN - 52
RS4 125 Maintenance
When using a funnel or any other element, make sure it is perfectly clean.
DO NOT GO BEYOND THE "MAX" AND BELOW THE "MIN" LEVEL MARK TO AVOID SEVERE
ENGINE DAMAGE.
• Top-up the oil in the reservoir until you reach the correct level.
Replacement
• Start the engine and let it idle for a few minutes; in this way, it is easier to drain the oil during
the subsequent drainage stage.
CAUTION
OIL BECOMES VERY HOT WHEN THE ENGINE IS HOT; BE CAREFUL NOT TO GET BURNED
WHEN CARRYING OUT THE OPERATIONS DESCRIBED BELOW.
MAIN - 53
Maintenance RS4 125
Recommended products
ENI I-RIDE PG 5W - 40 Engine oil
SAE 5W - 40. As an alternative for recommended
oils, top-branded oils that meet or exceed the re-
quirements of CCMC G-4 A.P.I. SG specifications
can be used.
Characteristic
Engine oil
1,200 cm³ (73.23 cu.in)
TIGHTEN UP THE FILLER CAP AND MAKE SURE THE OIL DOES NOT SEEP.
CHECK REGULARLY THAT THERE ARE NO LEAKS IN THE CRANKCASE COVER GASKET.
DO NOT RIDE THE MOTORCYCLE WITH INSUFFICIENT LUBRICATION OR WITH CONTAMINA-
TED OR INCORRECT LUBRICANTS AS THIS ACCELERATES THE WEAR AND TEAR OF THE
MOVING PARTS AND CAN CAUSE IRRETRIEVABLE DAMAGE.
• Remove the fairing lug beforehand and empty the engine oil.
MAIN - 54
RS4 125 Maintenance
Gearbox Oil
Air filter
MAIN - 55
Maintenance RS4 125
• Clean the air filter (4) with a blast of compressed air direct from the inner to the outer part
of the filter.
• Clean the external side of the air filter (4) with a clean cloth.
• Clean the inside of the filter casing (5) and the intake ducts (6) with a clean cloth.
CAUTION
WHEN CLEANING THE FILTERING ELEMENT, CHECK THAT IT IS NOT TORN. IF IT IS, REPLACE
THE FILTERING ELEMENT.
AIR FILTER REPLACEMENT
Replace the air filter (1) with a new one of the same type.
NOTE
NEVER REUSE AN OLD FILTER.
Cooling system
MAIN - 56
RS4 125 Maintenance
DO NOT USE THE SCOOTER IF THE COOLANT LEVEL IS BELOW THE MINIMUM MARK.
WHEN CARRYING OUT MAINTENANCE OPERATIONS, IT IS ADVISABLE TO WEAR LATEX
GLOVES.
TAKE YOUR SCOOTER TO AN OFFICIAL aprilia DEALER TO HAVE COOLANT CHANGED.
Coolant solution is 50% water and 50% antifreeze fluid.
This is the ideal mixture for most operating temperatures and provides good corrosion protection.
It is advisable to use the same mixture even in hot weather as this minimises loss due to evaporation
and the need of frequent top-ups.
Thus, less evaporated water means fewer mineral salt deposits in the radiators, which helps preserve
the efficiency of the cooling system.
When the external temperature drops below zero degrees centigrade, check the cooling system fre-
quently and add more antifreeze solution if needed (up to 60% max.).
Use distilled water in the coolant mixture to avoid damaging the engine.
DO NOT REMOVE THE EXPANSION TANK PLUG WHEN THE ENGINE IS HOT, SINCE COOLANT
IS UNDER PRESSURE AND VERY HOT.
CAUTION
WAIT FOR THE ENGINE TO COOL DOWN BEFORE CHECKING OR TOPPING-UP COOLANT
LEVEL.
Level check
Top-up
MAIN - 57
Maintenance RS4 125
• Top-up the coolant until the liquid level reaches the upper notch at the front of the coolant
tank.
• Do not exceed this level; otherwise, the coolant will spill during engine operation.
• Refit the filler cap.
• Check the liquid level, as described above.
CAUTION
IF THERE IS AN EXCESSIVE CONSUMPTION OF COOLANT OR WHEN THE EXPANSION TANK
REMAINS EMPTY, CHECK THAT THERE ARE NO LEAKS IN THE CIRCUIT.
NOTE
COOLANT IS TOXIC IF INGESTED; CONTACT WITH YOUR EYES OR SKIN MAY CAUSE IRRITA-
TION. IF THE FLUID GETS IN CONTACT WITH THE EYES OR SKIN, RINSE REPEATEDLY WITH
PLENTY OF WATER AND SEEK MEDICAL ADVICE. IF SWALLOWED, INDUCE VOMITING, RINSE
MOUTH AND THROAT WITH PLENTY OF WATER AND SEEK MEDICAL ADVICE IMMEDIATELY.
Braking system
Level check
MAIN - 58
RS4 125 Maintenance
MAIN - 59
Maintenance RS4 125
Top-up
MAIN - 60
RS4 125 Maintenance
• In case of excessive travel of the brake lever or poor performance of the braking system,
purge the air in the system.
Recommended products
AGIP BRAKE 4 Brake fluid
As an alternative to the recommended fluid, other
fluids that meet or exceed the required specifica-
tions may be used. SAE J1703, NHTSA 116 DOT
4, ISO 4925 Synthetic fluid
MAIN - 61
Maintenance RS4 125
Clutch system
• Lubricate the clutch wire frequently with an appropriate grease to avoid early wear and cor-
rosion.
MAIN - 62
INDEX OF TOPICS
Components arrangement
KEY:
1. Stop switch
2. Taillight
3. Injector
ELE SYS - 64
RS4 125 Electrical system
4. Battery
5. Main fuses
6. Fan relay
7. Light relay
8. Front headlight assembly
9. Start-up relay
10.Electric fan
11.Lambda probe
12.Fuel reserve sensor
13.Oil pressure sensor
14.Fuel pump
15.Coil/ECU
16.Injection relay
17.Secondary fuses
18.Instrument panel
19.Turn indicators
20.Regulator
21.Spark plug boot
22.Control unit
23.Temperature sensor
24.Starter motor
25.Neutral sensor
26.Stand sensor
ELE SYS - 65
Electrical system RS4 125
• Connection and vibration absorption sponge on the license plate bracket light - REAR SEC-
TION, TABLE B2.
• Check the ECU connection cable and insertion of protective rubber - CENTRAL SECTION,
TABLE E4.
• Check correct securing of metallic bracket screw on the throttle body - CENTRAL SECTION,
TABLE E5.
• Check injector connection - CENTRAL SECTION, TABLE E3.
• Check water temperature sensor connection, - CENTRAL SECTION, TABLE E4.
• Check injector and water temperature sensor cable clip - CENTRAL SECTION, TABLES
E4-E5.
• Check correct insertion of the H.V. cable with the coil - CENTRAL SECTION, TABLE D1.
• Check the coil connection and correct fixing of the coil ground eyelet - CENTRAL SECTION,
TABLE D2
• Check correct insertion of the engine oil hood. CENTRAL SECTION, TABLE K1.
• Check the starter motor ground clamp, starter motor positive and relative hood - CENTRAL
SECTION, TABLE L1.
• Check the Neutral cable clamp - CENTRAL SECTION, TABLES J6-M.
• Check the fuel reserve sensor connection - CENTRAL SECTION, TABLE N2.
ELE SYS - 66
RS4 125 Electrical system
The connectors in the list are circled in "green" in the different pictures.The listed connectors
are considered more critical than the others because their disconnection could cause the ve-
hicle to stop or malfunction. Obviously, the correct connection of the other connectors is also
important and essential for proper vehicle operation.
It is also important and essential that the instructions regarding the routing and fixing of the cable har-
ness in the various areas are followed meticulously in order to guarantee functionality and reliability.
WIRING DIAGRAM
Ensure that you have the most up to date electrical circuit diagram, downloading it from the network.
Electrical circuit diagrams RS4 125 MY2011 - 898459.
1. Front section
2. Central section
3. Rear section
Front side
ELE SYS - 67
Electrical system RS4 125
TABLE A4
3. Lights relay
6. High beam bulb
7. Clamp.
8. Grey sheathing. Indicates that the connector
must be connected to the central bulb (high beam).
ELE SYS - 68
RS4 125 Electrical system
TABLE A5
1. Daylight running light (5W).
4. Low beam light (35W).
6. High beam light (35W).
ELE SYS - 69
Electrical system RS4 125
TABLE C2
12. Rubber clamp
ELE SYS - 70
RS4 125 Electrical system
D TABLES - SUPPORT
TABLE D1
13. Clamp: the clamp must secure all cables inside
the instrument holder support; the main cable har-
ness must be secured with the clamp on the grey
taping.
14. Main cable harness.
TABLE D2
15. Front headlamp cable harness connector.
ELE SYS - 71
Electrical system RS4 125
ELE SYS - 72
RS4 125 Electrical system
ELE SYS - 73
Electrical system RS4 125
ELE SYS - 74
RS4 125 Electrical system
Central part
TABLE A2
ELE SYS - 75
Electrical system RS4 125
TABLE A3
TABLE A4
TABLE A5
Free hole for chassis ground
ELE SYS - 76
RS4 125 Electrical system
TABLE C
6. Main cable harness
CAUTION
THE ADHESIVE CABLE TIES (6) MUST BE POSITIONED
WITH THE CABLE INTAKE OPENING UPWARD SO THAT
THE CABLE HARNESS IS INSERTED FROM THE TOP
SIDE.
TABLE D2
10. Elastic clip.
23. Coil ground.
24. Coil connector.
CAUTION
CONNECT THE COIL CONNECTOR (24).
FIT THE BLUE GROUND CABLE (23) ON THE ELASTIC
CLIP (10).
ELE SYS - 77
Electrical system RS4 125
TABLE E2
12. Protective rubber
13. Bracket retainer screw
14. Metallic bracket
15. Free hole for running injector cable and water
sensor cable cable ties.
CAUTION
POSITION THE METAL BRACKET (14), BLOCKING THE
ECU AND FIXING WITH SPECIFIC SCREW (13).
TABLE E3
16. Connector
17. Injector
CAUTION
CONNECT THE CONNECTOR (16) TO THE INJECTOR AND
ENSURE THAT IT IS CORRECTLY CONNECTED.
TABLE E4
CAUTION
CONNECT THE GREEN WATER TEMPERATURE SENSOR
(18) AND ENSURE THAT IT IS CORRECTLY CONNECTED.
CHECK THE POSITIONING OF THE INSULATING SLEEVE.
ELE SYS - 78
RS4 125 Electrical system
TABLE E5
19. Clamp
CAUTION
JOIN THE TWO CABLES (WATER SENSOR - INJECTOR),
SECURE THEM WITH A CLAMP ANCHORING THEM TO
THE METALLIC BRACKET THROUGH THE FREE HOLE ON
THE BRACKET ITSELF.
TABLE G2
CAUTION
POSITION THE GREY REFERENCE PRESENT ON THE CA-
BLE HARNESS ON THE RESPECTIVE CLAMP AND CLOSE
IT, POSITIONING THE CABLE HARNESS AS SHOWN IN
THE PHOTO.
ELE SYS - 79
Electrical system RS4 125
TABLE H - FUSES
21. Main fuses.
22. Auxiliary fuses.
23. Reserve fuses (auxiliary).
24. Reserve fuses (main)
CAUTION
POSITION THE FUSES ON THE METALLIC BRACKET OB-
SERVING THE POSITION:
- GREEN AND BROWN FUSES (RIGHT) - Main (21)
- YELLOW AND BLUE FUSES (LEFT) - Auxiliary (22)
I TABLES
TABLE I1
25. Engine - chassis ground lead
26. Screw and spring washer
TABLE I2
25. Engine - chassis ground lead
CAUTION
CHECK CORRECT SECURING OF THE ENGINE - CHASSIS
CABLE.
ELE SYS - 80
RS4 125 Electrical system
TABLE J2
30. Electric fan connector: insert the connector in
the specific tongue in the battery support after con-
necting it.
TABLE J3
31. 80A 12V Starter relay
ELE SYS - 81
Electrical system RS4 125
TABLE J4
ELE SYS - 82
RS4 125 Electrical system
TABLE J6
32. Horn cable: the horn cable must be secured
with the two indicated clamps.
33. Five clamps for fixing horn cable, stand sensor
cable, neutral cable.
34. Neutral cable.
35. Stand sensor cable.
ELE SYS - 83
Electrical system RS4 125
ELE SYS - 84
RS4 125 Electrical system
TABLE N2
37. Fuel sensor and pump cable.
CAUTION
CONNECT THE RESERVE FUEL SENSOR TO THE MAIN
CABLE HARNESS.
ELE SYS - 85
Electrical system RS4 125
TABLE N3
6. Pre-fitted cable ties.
37. Fuel sensor and pump cable.
CAUTION
PASS THE BRANCH ON THE LEFT SIDE OF THE TANK,
INSERTING IT ON THE SPECIFIC CABLE TIES (6) PREVI-
OUSLY FITTED.
TABLE N4
39. Fuel pump cable
CAUTION
CONNECT THE FUEL PUMP AND CHECK THAT THE CON-
NECTOR IS PROPERLY CONNECTED; CHECK THAT THE
THREE RED CAPS ARE STILL IN THE SEAT AFTER CON-
NECTION.
ELE SYS - 86
RS4 125 Electrical system
Back side
ELE SYS - 87
Electrical system RS4 125
TABLE B2
CAUTION
VERIFY THE PRESENCE OF THE VIBRATION ABSORP-
TION SPONGE BETWEEN THE SUPPORT AND THE LI-
CENSE PLATE LIGHT.
ELE SYS - 88
RS4 125 Electrical system
TABLE C
• Breather pipe
TABLE D2 - Step 2
TABLE D3
9. Insert the diagnostics plug in the specific sup-
port.
ELE SYS - 89
Electrical system RS4 125
TABLE E2
11. Taillight Cable harness
12a. Clamps: join the taillight cable harness and the diagnostics cable.
12b. Optional clamp
12c. Clamp.
TABLE E3
10. Connector positioning.
11. Taillight cable harness.
13. Main cable harness.
ELE SYS - 90
RS4 125 Electrical system
TABLE E4
11. Taillight cable harness.
14. LED Rear light
15. Cable guide.
ELE SYS - 91
Electrical system RS4 125
Key
1. MULTIPLE CONNECTORS
2. ECU
3. FRONT LEFT TURN INDICATOR
4. TAIL LIGHT BULB
ELE SYS - 92
RS4 125 Electrical system
ELE SYS - 93
Electrical system RS4 125
Colour key:
Ar Orange
Az Sky blue
B Blue
Bi White
G Yellow
Gr Grey
M Brown
N Black
R Red
Ro Pink
V Green
Vi Purple
ELE SYS - 94
RS4 125 Electrical system
Specific tooling
020331Y Digital multimeter
Dashboard
Diagnosis
Oil level
• If low oil level has been detected, check if the general warning light and the icon turn on.
There are no reference indicators.
• It is necessary to check if there is no engine oil left in the reservoir.
Low fuel
• In case of short circuit the general warning light does not turn on, no icon and no reference
indicator turns on. The low fuel orange light remains always on.
ELE SYS - 95
Electrical system RS4 125
Water temperature
ELE SYS - 96
RS4 125 Electrical system
• ODO
• TRIP I
• TRIP II
• MAX
Ignition circuit
Characteristic
Spark plug
NGK CR9EB
Electrode gap
0.5 mm (0.020 in)
ELE SYS - 97
Electrical system RS4 125
KEY:
1. MULTIPLE CONNECTORS
27. Battery
28. MAIN FUSES
30. Voltage regulator
31. ALTERNATOR
RECHARGING SYSTEM
ELE SYS - 98
RS4 125 Electrical system
• Take the measurement; The correct value is determined by the value measured for each
stage in which from time to time the resistance of the tester wires is subtracted, obtained by
touching the two lugs.
Example:
ELE SYS - 99
Electrical system RS4 125
• If there is a significant difference between one stage and another (other than 0.20 Ohm),
this means that the alternator is defective and must be replaced.
RESISTANCE MEASUREMENT
Winding stage Ambient temperature (ohm) Afterwards heat stabilisation (ohm)
Stage 1 0.15 - 0.30 0.20 - 0.35
Stage 2 0.15 - 0.30 0.20 - 0.35
Stage 3 0.15 - 0.30 0.20 - 0.35
Empty voltage
• For a correct detection of the alternator voltage, the measurements must be carried out using
alternatively the 3 ends of the free cables: stage "1" (outgoing cables from pins 2 and 4),
stage "2" (outgoing cables from pins 2 and 6), stage "3" (outgoing cables from pins 4 and
6).
• Start the engine and carry out the measurement.
• If there is a significant difference between one stage and another (other than 15 V), this
means that the alternator is defective and must be replaced.
CAUTION
WITH THE ENGINE HOT THE VALUES RECORDED ARE ON AVERAGE 4-5 V LESS THAN THOSE
DETECTED WITH THE ENGINE COLD.
EMPTY VOLTAGE
rpm 2000 6000 8000
Vm linked voltage Reference values (V rms) 20 - 30 75 - 85 95 - 105
Voltage on battery poles with engine speed always between 3000 - 5000 RPM
• Start the engine, after about one minute of operating bring the speed to 3000-5000 RPM,
then measure with a tester the voltage at the battery poles that must always be between
13V and 15V. Otherwise, if the correct operation of the alternator has already been checked,
replace the regulator.
CAUTION
PERFORM THE CHECK DESCRIBED ABOVE WITH A BATTERY IN GOOD CONDITION (START
VOLTAGE ABOUT 13V) MAKING SURE THAT THERE ARE NO ELEMENTS IN THE SHORT CIR-
CUIT.
KEY:
1. MULTIPLE CONNECTORS
2 ECU control unit
9. SIDE STAND
13. CLUTCH SWITCH
17. Right light switch
18. IGNITION SWITCH
25. START-UP RELAY
26. STARTER MOTOR
27. Battery
29. Secondary fuses
33. GEAR IN NEUTRAL SWITCH
Correct value 50 - 60 A.
STARTER COMMAND
Function
Commands engine starting through the injection control unit.
Operation / Operating principle
The starter button, the brake switches, the No. 25 starter command relay and the injection control unit
between PIN 5 and 10 are involved.
ELECTRICAL ERRORS
Starter command P0170 - shorted to positive.
Error cause
Shorted to positive: excessive voltage at PIN 10 of the control unit connector.
Troubleshooting
Shorted to positive:
• This malfunction is detected with a brake activated and the starter button pressed (voltage
of 12V read at PIN 5).
• If the battery voltage does not drop (thanks to the absorption of the No. 25 starter command
relay excitation coil) the control unit understands that PIN 10 is shorted to battery.
• Restore the cabling (if the short is in the cabling) or the relay (if the short is in the relay).
NOTE
IN CASE OF SHORT TO GROUND / OPEN CIRCUIT NO ERROR WILL APPEAR: SEE THE TROU-
BLESHOOTING CHAPTER, THE ENGINE DOES NOT START.
Horn control
level indicators
Lights list
key:
REAR LIGHT
Rear tail light / license plate light /stop light
12 V - 5 / 21 W
FRONT HEADLAMP
(Halogen) low beam light: 12 V - 55 W H 11
(Halogen) high beam light: 12 V - 55 W H 11
Tail light: 12V - 5W
Fuses
AUXILIARY FUSES
- 20A fuse: rear light unit, blinker, light relay, front
headlight assembly
- 15A fuse: start-up relay, injection relay, instru-
ment panel, fan relay, control unit.
- 20A and 15A fuses: spare fuses
MAIN FUSES
- 30A fuse: battery recharge, control unit
- 7.5A fuse: fan.
- 7.5A and 30A fuses: spare fuses
Control unit
Battery
• turn indicators the proper flashing function is not ensured, according to the Regulations;
• headlamps: it is not ensured that the light intensity is the same as having a normal compo-
nent function;
• instrument panel: malfunctions can be checked in the screen page of the display and in the
instrument panel functions; it is possible that the speed indications are not right.
Battery maintenance
If the vehicle is not be used for a certain time (1 month or more), the battery needs to be recharged
periodically.
The battery runs down completely in about three months. If it is necessary to refit the battery in the
vehicle, be careful not to reverse the connections, remembering that the ground wire (black) marked
(-) must be connected to the -negative clamp while the other two red wires marked (+) must be con-
nected to the clamp marked with the +positive sign.
1) Recharging the battery
First detach the negative terminal before removing the battery from the vehicle.
Regular bench charging must be carried out with the specific battery charger, (single) or (multiple),
setting the battery charger selector to the type of battery to be recharged. Connections to the power
supply source must be implemented by connecting the corresponding poles (+ to+ and - to -).
2) Cleaning the battery
The battery should always be kept clean, especially its top side, and the terminals should be coated
with petroleum jelly.
CAUTION
NEVER USE FUSES WITH A CAPACITY HIGHER THAN THE RECOMMENDED CAPACITY. USING
A FUSE OF UNSUITABLE RATING MAY SERIOUSLY DAMAGE THE VEHICLE OR EVEN CAUSE
A FIRE.
CAUTION
ORDINARY DRINKING WATER CONTAINS MINERAL SALTS THAT ARE HARMFUL TO THE BAT-
TERY. CONSEQUENTLY, ONLY USE DISTILLED WATER.
CAUTION
TO ENSURE MAXIMUM PERFORMANCE THE BATTERY MUST BE CHARGED BEFORE USE.
LACK OF PROPER CHARGING OF THE BATTERY BEFORE FIRST USE AT LOW ELECTROLYTE
LEVEL, CAN LEAD TO PREMATURE BATTERY LIFE.
Specific tooling
020333Y Single battery charger
020334Y Multiple battery charger
WARNING
BATTERY ELECTROLYTE IS TOXIC AND IT MAY CAUSE SERIOUS BURNS. IT CONTAINS SUL-
PHURIC ACID. AVOID CONTACT WITH YOUR EYES, SKIN AND CLOTHING. IF IT ACCIDENTALLY
COMES INTO CONTACT WITH YOUR EYES OR SKIN, WASH WITH ABUNDANT WATER FOR
APPROX. 15 MIN. AND SEEK IMMEDIATE MEDICAL ATTENTION.
IF ACCIDENTALLY SWALLOWED, IMMEDIATELY DRINK LARGE QUANTITIES OF WATER OR
MILK FOLLOWED BY MAGNESIUM MILK, BEATEN EGG OR VEGETABLE OIL. SEEK IMMEDIATE
MEDICAL ATTENTION.
BATTERIES PRODUCE EXPLOSIVE GASES; KEEP CLEAR OF NAKED FLAMES, SPARKS OR
CIGARETTES; VENTILATE THE AREA WHEN RECHARGING INDOORS.
ALWAYS WEAR EYE PROTECTION WHEN WORKING IN THE PROXIMITY OF BATTERIES.
KEEP OUT OF THE REACH OF CHILDREN.
1) Battery preparation
Position the battery on a flat surface. Remove the
adhesive sheet closing cells and proceed as quick-
ly as possible to run the subsequent activation
phases.
2) Electrolyte preparation.
Remove the container of the electrolyte from the
pack. Remove and preserve cover strips from the
container, in fact, the strip will later be used as a
closing cover.
Note: Do not pierce the sealing of the container or
the container itself because inside there is sulphu-
ric acid.
Make sure air bubbles are rising from all six filling holes. Leave the container in this position for 20
minutes or more.
Note:If there are no air bubbles coming out of the filling holes, lightly tap the bottom of the container
two or three times. Do not remove the container from the battery.
5) Take out the container.
Make sure all the electrolyte in the battery is drained. Gently tap the bottom of the container if electrolyte
remains in the container. Now, gently pull the container out from the battery, only do this when the
container is completely empty, and proceed immediately to the next point.
6) Battery closing.
Insert the airtight cover strips into the filling holes. Press horizontally with both hands and make sure
that the strip is levelled with the top part of the battery.
Note:To do this, do not use sharp objects that could damage the closing strip, use gloves to protect
your hands and do not bring your face close to the battery.
The filling process is now complete.
Do not remove the strip of caps under any circumstances, do not add water or electrolyte.
Place the battery down for 1 to 2 hours prior to the charging from the battery.
i - The battery is now completely activated, disconnect the battery charger from the fuel supply grid,
disconnect the clamps from the battery and proceed to fitting the battery on the vehicle.
BATTERY
(12 V - B9 - B)
In case of malfunction check first that the recharge
system works properly. To check the battery, re-
move it from the vehicle, and proceed as follows;
visually check that:
- there are no signs of sulphation (signalled by
white colouring of one or more cells);
- the electrolyte level is between the two "MIN" and
"MAX" reference notches;
- the container (outer casing) does not leak.
Charge the battery slowly for at least 10 hours.
With a densimeter check the electrolyte density at
every cell after recharging. If the density is below
1.26 at any cell or if the off-load voltage is lower
than 12V, the battery surely needs to be replaced.
Speed sensor
Function
To indicate the vehicle speed by reading the front
wheel turning speed.
Operation / Operating principle
Magnetoresistive sensor: generation of a square
wave.
Pin-out:
A. Control unit power
B. Control unit ground
C. Signal
ELECTRICAL ERRORS
Sensor/vehicle speed signal P0500 - over maximum limit/ signal not valid.
Error cause
Faulty sensor or cabling, interference on the signal.
Troubleshooting
Function
Serves the purpose of communicating the engine
temperature to the control unit in order to optimise
performance.
Operation / Operating principle
NTC type sensor (resistance sensor, inversely
variable with temperature).
Pin-out:
ELECTRICAL ERRORS
Engine temperature sensor P0115 - open circuit or shorted to positive / shorted to negative.
Error cause
Open circuit or shorted to positive: interruption of the circuit or excessive voltage at PIN 13 of the control
unit connector.
Shorted to negative: null voltage between PIN 13 and 15 of the control unit connector.
Troubleshooting
The circuit is open:
Shorted to positive:
• With the sensor connector and the control unit disconnected, verify that the fault is shorted
with the battery positive of sensor connector PIN 3 (or control unit PIN 13) and restore the
cabling.
Shorted to negative:
Lambda sensor
Function
In charge of telling the control unit whether the
mixture is lean or rich.
Operation / Operating principle
Based on the difference of oxygen in the exhaust
fumes and the environment, this generates volt-
age which is read and interpreted by the injection
control unit. It does not require an external supply
source but, in order to work properly, it should
reach a high operating temperature: that is why
there is a heating circuit inside.
Pin-out:
• Verify continuity of the cabling between the sensor connector and the control unit connector:
Control unit PIN 11 - sensor PIN C and control unit PIN 12 - sensor PIN D. Restore the
cabling if necessary.
• If the cabling is intact and the error persists, proceed with the following checks.
Shorted to negative:
Lambda probe heater P0135 - shorted to positive / shorted to negative / open circuit.
Error cause
Shorted to positive: excessive voltage at PIN 31 of the control unit connector.
Shorted to negative: lack of insulation from ground on the sensor connector PIN A.
The circuit is open: interruption of the circuit.
Troubleshooting
Shorted to positive:
Shorted to negative:
Injector
Function
To supply the correct amount of petrol at the right timing.
Operation / Operating principle
Injector coil is excited for the petrol passage to open.
Pin-out:
Shorted to negative:
• Disconnect the injector connector, turn the key to ON and activate the component through
the diagnostics instrument.
• Verify the presence of voltage at the ends of the injector connector; if there is no voltage,
restore the cable harness, otherwise proceed with the following checks.
Fuel pump
CAUTION
BEFORE CARRYING OUT ANY TROUBLESHOOTING, CAREFULLY READ THE GENERAL TROU-
BLESHOOTING CONCEPTS FOR ELECTRICAL DEVICES AT THE BEGINNING OF THE CHECK
AND CONTROL SECTION IN THE ELECTRICAL SYSTEM CHAPTER.
ELECTRICAL ERRORS
Fuel pump relay P0230 - shorted to positive / shorted to negative / open circuit.
Error cause
Shorted to positive: excessive voltage at PIN 22 of the control unit connector.
Shorted to negative: null voltage at PIN 2 of the injection relay.
The circuit is open: interruption of the circuit.
Troubleshooting
Shorted to positive:
• Disconnect the injection relay (No. 35 on the electrical circuit diagram), turn the key to the
ON position and activate the relay through the diagnostics instrument.
• Verify the presence of voltage between relay connector PIN 1 and 2 toward the cabling.
• If no voltage is read, disconnect the control unit and verify insulation from battery positive
of the relay PIN 1 (or control unit PIN 22). Restore the cabling if necessary.
Shorted to negative:
• Disconnect the injection relay (No. 35 on the electrical circuit diagram) and the control unit.
• Verify ground insulation of the relay connector PIN 1 and 2 toward the cabling: if there is no
insulation, restore the cabling.
• Disconnect the injection relay (No. 35 on the electrical circuit diagram) and the control unit.
• Verify continuity of the cabling between the relay and control unit: Relay PIN 1 - control unit
PIN 22. Restore the cabling if necessary.
Coil
Check
A tester can be used for the check. In every case
the continuity of the primary and secondary wind-
ings must be checked. The reading in ohms does
not need to be exact but, if the windings are intact,
their continuity must be detected with the resist-
ance values indicated above.
Function
Allows generation of the electrical discharge on
the spark plug, with an increase of voltage.
Pin-out:
CAUTION
BEFORE CARRYING OUT ANY TROUBLESHOOTING, CAREFULLY READ THE GENERAL TROU-
BLESHOOTING CONCEPTS FOR ELECTRICAL DEVICES AT THE BEGINNING OF THE CHECK
AND CONTROL SECTION IN THE ELECTRICAL SYSTEM CHAPTER.
ELECTRICAL ERRORS
H.V. Coil P0351 - shorted to positive / open circuit or shorted to negative.
Error cause
Shorted to positive: excessive voltage at PIN 1 of the control unit connector.
Circuit open or shorted to negative: interruption of the circuit or null voltage at PIN 1 of the control unit
connector.
Troubleshooting
Shorted to positive:
• Disconnect the coil connector, turn the key to ON and activate the component through the
diagnostics instrument.
• Verify the presence of voltage on the coil connector PIN 2: if present, restore the cabling,
otherwise replace the coil.
• Carry out the check procedure of the coil and control unit connectors.
• Verify continuity of the cabling between the coil and control unit: Coil PIN 2 - control unit PIN
1. In the absence of continuity restore the cabling.
• Verify, with the key turned ON, the presence of voltage on the coil connector PIN 1. If no
voltage is read, verify the continuity of the cabling between coil and injection relay (No. 35
on the electrical circuit diagram): Coil PIN 1 - relay PIN 3.
• If the above tests provided a positive result, the coil should be replaced.
Shorted to negative:
Neutral sensor
Switch check
With a tester check the values between the two
terminals:
- With the stand unfolded, the tester indicates an
infinite resistance value.
- With the stand folded up, resistance is equal to 0
Ohm.
Function
Radiator fan and coolant - Operation.
Operation / Operating principle
The control unit closes the fan control relay excitation circuit to ground until the temperature drops.
CAUTION
BEFORE CARRYING OUT ANY TROUBLESHOOTING, CAREFULLY READ THE GENERAL TROU-
BLESHOOTING CONCEPTS FOR ELECTRICAL DEVICES AT THE BEGINNING OF THE CHECK
AND CONTROL SECTION IN THE ELECTRICAL SYSTEM CHAPTER.
ELECTRICAL ERRORS
Fan relay P0480 - shorted to positive / shorted to negative / open circuit.
Error cause
Shorted to positive: excessive voltage at PIN 24 of the control unit connector.
Shorted to negative: null voltage at PIN 24 of the control unit connector.
The circuit is open: interruption of the circuit.
Troubleshooting
Shorted to positive:
• Disconnect the fan control relay (No. 42 on the electrical circuit diagram) and, turning the
key to the ON position, measure the voltage read at the relay connector PIN 1 toward the
cabling: if the voltage is 12V restore the cabling. If the voltage is zero replace the relay.
Shorted to negative:
• Disconnect the fan control relay (No. 42 on the electrical circuit diagram) and the control
unit.
• Verify ground insulation of the cable between the fan control relay (PIN 1) and the control
unit (PIN 24). Restore the cabling if necessary.
• Carry out the check procedure of the control unit and relay connectors.
• Verify electrical continuity of the cable between the relay connector (PIN 1) and the control
unit connector (PIN 2).
• Verify electrical continuity of the cable between the relay connector (PIN 2) and the secon-
dary fuses.
• Verify continuity between relay PIN 1 and PIN 2. If there is no continuity replace the relay.
Connectors
ECU
Key
Dashboard
key:
1. GROUND
2. + LIVE
3. (Not connected)
4. GROUND FOR SENSORS
5. RIGHT TURN INDICATOR WARNING
LIGHT
6. EFI WARNING LIGHT
7. HIGH BEAM WARNING LIGHT
8. LEFT TURN INDICATOR WARNING LIGHT
9. IMMOBILIZER / ABS WARNING LIGHT (not
used)
10.NEUTRAL WARNING LIGHT
11.WATER TEMPERATURE WARNING
LIGHT
12.OIL PRESSURE WARNING LIGHT
13.RPM INPUT
14.CONFIGURATION PIN
15.(Not connected)
16.(Not connected)
17.(Not connected)
18.SPEED SENSOR
19.FUEL RESERVE SENSOR
20.+ BATTERY
Vehicle preparation
See also
Air box
Side fairings
Removing the expansion
tank
Removing the
radiator
Coolant replacement
Fuel tank
Lower cowl
See also
ENG VE - 127
Engine from vehicle RS4 125
Vehicle preparation
ENG VE - 128
RS4 125 Engine from vehicle
ENG VE - 129
Engine from vehicle RS4 125
ENG VE - 130
RS4 125 Engine from vehicle
ENG VE - 131
Engine from vehicle RS4 125
ENG VE - 132
RS4 125 Engine from vehicle
Specific tooling
866714 Swingarm adjustment
ENG VE - 133
Engine from vehicle RS4 125
ENG VE - 134
RS4 125 Engine from vehicle
ENG VE - 135
Engine from vehicle RS4 125
ENG VE - 136
RS4 125 Engine from vehicle
ENG VE - 137
Engine from vehicle RS4 125
• Fit the previously removed units following the reverse order of the vehicle preparation de-
scription.
ENG VE - 138
INDEX OF TOPICS
ENGINE ENG
Engine RS4 125
Gearbox
Gearbox shafts
See also
Crankcase opening
COUPLING CLASSES
The gears of the primary drive are classified according to the coupling with the gear of the clutch housing
and with the gear of the balancing countershaft and follow the logic shown in the tables listed below:
ENG - 140
RS4 125 Engine
• Check the contact zone on fork (1) and the driving pin (2) of the forks for wear.
• Check the desmodromic drum (4) grooves (3) for wear.
• Make sure that both ball bearings rotate freely and check if there are signs of corrosion.
ENG - 141
Engine RS4 125
Specific tooling
00H05600351 Guide for oil seal
Starter motor
STARTER MOTOR
pos. Description Type Quantity Torque Notes
1 Starter motor fixing screw M6x25 2 11 - 13 Nm (8.11 - 9.58 -
lbf ft)
STARTER MOTOR
ENG - 142
RS4 125 Engine
Generator side
FLYWHEEL COVER
pos. Description Type Quantity Torque Notes
1 Flywheel cover fastener screw M6 10 11 - 13 Nm (8.11 - 9.58 -
lbf ft)
ENG - 143
Engine RS4 125
IGNITION UNIT
pos. Description Type Quantity Torque Notes
1 Flywheel rotor fixing screw M14x1.5 1 83 - 90 Nm (61.21 - -
66.38 lb ft)
ENG - 144
RS4 125 Engine
Specific tooling
865259 Flywheel retainer
Specific tooling
864868 Flywheel extractor
ENG - 145
Engine RS4 125
ENG - 146
RS4 125 Engine
Freewheel removal
See also
ENG - 147
Engine RS4 125
Clutch side
CLUTCH COVER
pos. Description Type Quantity Torque Notes
1 Clutch cover fixing screw M6x35 10 11 - 13 Nm (8.11 - 9.58 -
lbf ft)
2 Oil filter cover M56x1.5 1 24 - 26 Nm (17.70 - -
19.17lbf ft)
3 Oil pressure sensor M10 1 12 - 14 Nm (8.85 - 10.32 -
lbf ft)
ENG - 148
RS4 125 Engine
CLUTCH
pos. Description Type Quantity Torque Notes
1 Clutch spring screw M5 5 3.5 - 4.5 Nm (2.58 - 3.31 -
lbf ft)
2 Clutch housing retainer nut M12 1 35 - 45 Nm (25.81 - -
33.19 lbf ft)
ENG - 149
Engine RS4 125
ENG - 150
RS4 125 Engine
ENG - 151
Engine RS4 125
Specific tooling
00H05300041 Clutch retainer
ENG - 152
RS4 125 Engine
Characteristic
Driving plates thickness
2.85 - 2.95 mm (0.112 - 0.116 in)
Number of driving plates
5
Driven plates thickness
1.46 - 1.53 mm (0.057 - 0.06 in)
Number of driven plates
4
COUPLING CLASSES
The gears that are coupled to each other: clutch housing, first gear shaft and balancing countershaft,
indicate the coupling classes; in this regard, see section "Checking the primary shaft" within the topic
"Gearshift".
ENG - 153
Engine RS4 125
ENG - 154
RS4 125 Engine
Characteristic
Minimum wear limit in the release position of
the individual clutch springs
31.6 mm (1.24 in)
ENG - 155
Engine RS4 125
Specific tooling
00H05300041 Clutch retainer
• Insert the disc covered with the friction material into the bell.
ENG - 156
RS4 125 Engine
Crankcase
ENGINE CRANKCASE
pos. Description Type Quantity Torque Notes
1 Crankcase halves union M6 12 11 - 13 Nm (8.11 - 9.58 -
lbf ft)
ENG - 157
Engine RS4 125
CRANKSHAFT
pos. Description Type Quantity Torque Notes
1 Countershaft gear retainer nut M10 1 35 - 45 Nm (25.81 - -
33.19 lbf ft)
Specific tooling
864486 Blocking the countershaft
See also
ENG - 158
RS4 125 Engine
Removing the
clutch cover
Removing the flywheel cover
Specific tooling
864486 Blocking the countershaft
ENG - 159
Engine RS4 125
Crankcase opening
Specific tooling
864486 Blocking the countershaft
See also
Removing the
ENG - 160
RS4 125 Engine
cylinder
ENG - 161
Engine RS4 125
See also
ENG - 162
RS4 125 Engine
Bearing removal
• Insertion of main shaft bearing: 020439Y+020359Y Removal of the main shaft bearing:
020358Y
• Insertion of desmo bearing: 020439Y+020357Y Removal of desmo bearing: 020891Y
• Insertion of secondary shaft roller bearing cage: 020891Y Removal of the secondary shaft
roller bearing cage:020363Y
• Insertion of countershaft bearing: 020412Y+020358Y Removal of countershaft bearing:
020375Y
LEFT CRANKCASE
• Insertion of main shaft bearing: 020439Y+020359Y Removal of the main shaft bearing:
020358Y
• Insertion of desmo roller bearing cage: 020375Y Removal of desmo roller bearing cage: use
universal extractor
ENG - 163
Engine RS4 125
• Insertion of secondary shaft roller bearing cage: 020363Y Removal of the secondary shaft
roller bearing cage: use universal extractor
• Insertion of countershaft roller bearing cage: 020483Y Removal of countershaft roller bear-
ing cage: 020364Y
Crankcase check
There are two classes of couplings highlighted on the crankcases (X-Y and S-T).
The coupling between the gears of the crankshaft and the first gear shaft has been classified into two
classes. These classes are defined according to the interaxial distance that exists between two ele-
ments:
The coupling between the gears of the first gear shaft and gear of the balancing countershaft has been
classified into two classes. These classes are defined according to the interaxial distance that exists
between two elements:
ENG - 164
RS4 125 Engine
NOTE
CRANKCASE SPARE PARTS ARE ALWAYS CLASS X.
Crankshaft check
• Before checking the crankcase halves, thoroughly clean all the surfaces and the oil pipes.
• For the crankcase half on the transmission side, take particular care when handling the
housing and hoses for the oil pump, the duct with the by-pass valve and the main bushings.
• As already described in the lubrication chapter, it is especially important that the by-pass
valve housing shows no wear that may impair the proper sealing of the lubrication pressure
adjustment ball.
• Check that the surfaces are free from dents or deformations, with special attention to both
the crankcase coupling and the cylinder-crankcase surfaces.
• Defects in the crankcase coupling gasket or the surfaces indicated in the figure can cause
a drop in the oil pressure and affect the lubrication pressure for the main bushings and the
connecting rod.
ENG - 165
Engine RS4 125
• Check that the surfaces that limit crankshaft axial clearance show no signs of wear. To
measure and check sizes follow the procedure described previously for checking crankshaft
axial clearance and dimensions.
COUPLING CLASSES
The gears that are coupled to each other: clutch housing, first gear shaft and balancing countershaft,
indicate the coupling classes; in this regard, see section "Checking the primary shaft" within the topic
"Gearshift".
Bushing selection
CRANKSHAFT DIAMETER
Specification Desc./Quantity
Class 1 MIN 32.480 mm (1.2787 in)
MAX 32.485 mm (1.2789 in)
Class 2 MIN 32.485 mm (1.2789 in)
MAX 32.490 mm (1.2791 in)
BUSHING THICKNESS
Specification Desc./Quantity
Red MIN 2.005 mm (0.0789 in)
MAX 2.010 mm (0.0791 in)
Blue MIN 2.010 mm (0.0791 in)
MAX 2.015 mm (0.0793 in)
Bearing fitting
• Insertion of main shaft bearing: 020439Y+020359Y Removal of the main shaft bearing:
020358Y
ENG - 166
RS4 125 Engine
LEFT CRANKCASE
• Insertion of main shaft bearing: 020439Y+020359Y Removal of the main shaft bearing:
020358Y
• Insertion of desmo roller bearing cage: 020375Y Removal of desmo roller bearing cage: use
universal extractor
• Insertion of secondary shaft roller bearing cage: 020363Y Removal of the secondary shaft
roller bearing cage: use universal extractor
• Insertion of countershaft roller bearing cage: 020483Y Removal of countershaft roller bear-
ing cage: 020364Y
NOTE: insertion of the roller bearing cages in line with the crankcase is recommended from the
inside to the outside.
Crankcase closing
See also
Assembling the gearbox
ENG - 167
Engine RS4 125
See also
Balancing
countershaft fitting
ENG - 168
RS4 125 Engine
ENG - 169
Engine RS4 125
ENG - 170
RS4 125 Engine
HEAD COVER
pos. Description Type Quantity Torque Notes
1 Spark plug M10 1 12 - 14 Nm (8.85 - 10.32 -
lbf ft)
2 Head cover fixing screw M6 4 10 - 12 Nm (7.38 - 8.85 -
lbf ft)
ENG - 171
Engine RS4 125
HEAD - VALVES
pos. Description Type Quantity Torque Notes
1 Head fastener screw, chain side M6x130 2 11 Nm (8.11 lbf ft) -
2 Exhaust side fixing stud bolt M8x40 2 12 Nm (8.85 lbf ft) -
3 Camshaft support fixing screw M6x40 8 10 Nm (7.38 lbf ft) -
4 Head fixing screw M8x166 4 25 Nm + 90° (18.44 lbf ft -
+ 90°)
5 Thermostat cover fixing screw M6x20 2 10 Nm (7.38 lbf ft) -
TIMING SYSTEM
pos. Description Type Quantity Torque Notes
1 Chain tensioner slider fulcrum fixing M6x16 1 10 Nm (7.38 lbf ft) Loctite 243
screw
2 Transmission timing gear fixing M8x40 1 27 Nm (19.91 lbf ft) Loctite 243
screw
ENG - 172
RS4 125 Engine
ENG - 173
Engine RS4 125
Specific tooling
864567 Locking pins timing camshafts
See also
Removing the
starter motor
ENG - 174
RS4 125 Engine
Specific tooling
865260 Camshaft sprocket lock
Cylinder head
ENG - 175
Engine RS4 125
ENG - 176
RS4 125 Engine
Specific tooling
020382Y011 Tool to remove/fit valves
ENG - 177
Engine RS4 125
Characteristic
Standard diameter - Bearing A
19.980 - 19.959 mm (0.7866 - 0.7858 in)
Minimum diameter allowed - Bearing A
19.95 mm (0.7854 in)
Inlet cam height
31.488 mm (1.23968 in)
Exhaust cam height
30.864 mm (1.21511 in)
• Check that the holes used for timing and their shoulders are not worn.
• If values measured are not within the specified limits or there are signs of wear, replace the
defective components with new ones.
Characteristic
Maximum axial clearance allowed:
0.4 mm (0.0157 in)
Valve check
• Measure the width of the sealing surface on the valve seats and on the valves themselves.
• If the sealing surface on the valve is wider than the specified limit, damaged in one or more
points or curved, replace the valve with a new one.
CAUTION
DO NOT CHANGE THE VALVE FITTING POSITION (RH - LH).
Characteristic
Minimum diameter allowed - Intake
3.96 mm (0.1559 in)
Minimum diameter allowed - Exhaust:
ENG - 178
RS4 125 Engine
Specific tooling
864567 Locking pins timing camshafts
ENG - 179
Engine RS4 125
ENG - 180
RS4 125 Engine
Characteristic
Valve clearance at intake
0.15 mm (0.0059 in)
Exhaust valve clearance
0,25 mm (0.0098 in)
• Fit the camshaft, the gears and the chain in their correct positions, using the references
located on the flywheel side of the crankcase.
• Fit the cam tower and tighten the eight screws to the prescribed torque.
• Fit the chain tensioner.
• Check for correct valve clearance.
ENG - 181
Engine RS4 125
Characteristic
Intake guide - standard diameter
4.012 mm (0.1579 in)
Intake guide: Wear limit
4.020 mm (0.1582 in)
Discharge guide - standard diameter
4.012 mm (0.1579 in)
Discharge guide: Wear limit
4.020 mm (0.1582 in)
Characteristic
Wear limit for the width of the mark on the valve
seat "V"
• Intake: 1.6 mm (0.0630 in)
• Outlet: 1.8 mm (0.0708 in)
ENG - 182
RS4 125 Engine
Characteristic
Valve spring length:
33.24 +/- 0.25 mm (1.3086 +/-0.0098 in)
• Using a trued bar, check that the head surface is not worn or distorted.
• Check that the camshaft bushings are not worn.
• Check that the head cover surface, the intake manifold and the exhaust manifold are not
worn.
Specific tooling
020382Y011 Tool to remove/fit valves
ENG - 183
Engine RS4 125
Cylinder-piston assembly
ENG - 184
RS4 125 Engine
CYLINDER - PISTON
pos. Description Type Quantity Torque Notes
1 Chain tensioner screw M8 1 6 Nm (4.43 lbf ft) -
CYLINDER REMOVAL
ENG - 185
Engine RS4 125
Specific tooling
865261 Piston locking pin
ENG - 186
RS4 125 Engine
Characteristic
Piston / cylinder
Piston pin hole - standard: 15.003 - 15.008 mm
(0.5907 - 0.5908 in)
Maximum piston / cylinder coupling clearance
after use
- top ring: 0.075 mm (0.0029 in)
- middle ring: 0.065 mm (0.0025 in)
- oil scraper: 0.25 mm (0.0098 in)
Standard piston / cylinder coupling clearance
ENG - 187
Engine RS4 125
cylinder check
Characteristic
Maximum run-out allowed:
0.05 mm
Characteristic
Pin
Minimum diameter: 14.995 mm (0.590 in)
Standard diameter: 15.0000 +0/-0.0030 mm (0.00012 in)
ANELLI DI TENUTA
Specification Desc./Quantity
Compression ring (top) 0.2 / 0.35 mm (0.0079 / 0.014 in)
Compression ring (middle) 0.2 / 0.35 mm (0.0079 / 0.014 in)
ENG - 188
RS4 125 Engine
Specification Desc./Quantity
Oil scraper ring 0.2 / 0.7 mm (0.0079 / 0.027 in)
Top ring maximum value 0.45 mm (0.18 in)
Middle ring maximum value 0.45 mm (0.18 in)
Characteristic
Rod small end
Maximum diameter: 15.023 mm (0.591 in)
Standard diameter: 15.010 - 15.018 mm (0.5910 - 0.5912 in)
ENG - 189
Engine RS4 125
Specific tooling
AP8140266 Dial gauge mounting
• Move the dial gauge diagonally and
measure the piston protrusion in rela-
tion to the reference surface.
• Calculate the necessary thickness of
the gasket, selecting it based on the
values shown in the table below.
Specific tooling
020287Y tool for sealing ring fitting
ENG - 190
RS4 125 Engine
ENG - 191
Engine RS4 125
Specific tooling
864567 Locking pins timing camshafts
ENG - 192
RS4 125 Engine
• Tighten the screws fixing the camshaft gears to the prescribed torque.
• Remove the pins on the camshafts.
• Remove the specific crankshaft locking tool.
• Tighten the screw on the crankcase.
• Check the valve clearance and adjust it if required.
• Refit the tappet cover.
ENG - 193
Engine RS4 125
Lubrication
OIL PUMP
pos. Description Type Quantity Torque Notes
1 Oil pump fixing screw M6x25 3 10 Nm (7.38 lbf ft) Loctite 243
ENG - 194
RS4 125 Engine
Conceptual diagrams
Removing
ENG - 195
Engine RS4 125
Inspection
Characteristic
Oil intake rotor
Thickness: 13.5 mm (0.53 in)
Oil supply rotor
Thickness: 8.5 mm (0.33 in)
Standard values
Radial clearance (1) between points of the rotor:
0.04 mm (0.0015 in)
Radial clearance (2) between points of the rotor: 0.08 mm
(0.003 in)
Radial clearance (3) between rotor 1 and the pump body: 0.04
mm (0.0015 in)
Radial clearance (3) between rotor 2 and the pump body: 0.05
mm (0.0019 in)
ENG - 196
RS4 125 Engine
Installing
ENG - 197
INDEX OF TOPICS
Circuit diagram
key:
1. Fuel tank
2. Fuel pump
3. Fuel pump ring nut
4. Fuel pump gasket
5. Fuel pipe
6. Fuel level sensor
7. Tank opening rod
8. Fuel breather pipe
Fuel pump
P SUPP - 199
Power supply RS4 125
Removing
See also
Fuel tank
Injection
P SUPP - 200
RS4 125 Power supply
Diagram
Key
P SUPP - 201
Power supply RS4 125
P SUPP - 202
RS4 125 Power supply
P SUPP - 203
INDEX OF TOPICS
SUSPENSIONS SUSP
RS4 125 Suspensions
Front
FRONT SUSPENSION
pos. Description Type Quantity Torque Notes
1 Screws fastening lower yoke to M8 2x2 25 Nm (8.43 lbf ft) -
sleeve
Key:
SUSP - 205
Suspensions RS4 125
1. Front tyre
2. Wheel bolt special screw
3. Washer
4. TE flanged screw
5. Front brake disc
6. Front wheel right external spacer
7. Sealing ring
8. Circlip
9. Bearing
10.Internal spacer
11.Bare front wheel
12.Front wheel pin
13.Tubeless valve
FRONT WHEEL
pos. Description Type Quantity Torque Notes
1 Front wheel spindle nut M14 1 78 Nm (8.85 lbf ft) -
2 Front disc fixing screw M6x20 6 12 Nm (8.85 lbf ft) -
SUSP - 206
RS4 125 Suspensions
WHEEL INSPECTION
NOTE
BALANCE THE WHEEL, IF A TYRE OR A WHEEL WAS REPLACED.
WARNING
SUSP - 207
Suspensions RS4 125
TYRES
WHEEL RIMS
SUSP - 208
RS4 125 Suspensions
• Follow the steps described in the front wheel removal in reverse, be very careful when po-
sitioning the components and the corresponding tightening torque.
SUSP - 209
Suspensions RS4 125
Handlebar
Front fork
The following operations are described for the Mingxing fork, but are identical for the operation
with the fork model Paioli, except where specified.
SUSP - 210
RS4 125 Suspensions
See also
Rear
mudguard
Removing the
front wheel
PAIOLI FORKS
CAUTION
THE FOLLOWING PROCEDURES ARE FOR A SINGLE WHEEL CARRIER STANCHION/SLEEVE
ASSEMBLY, BUT ARE APPLICABLE TO BOTH.
• Fit the fork in the vice using the special
Teflon grips.
SUSP - 211
Suspensions RS4 125
CAUTION
BEFORE PROCEEDING WITH THE FOLLOWING OPERATIONS GET A SUITABLE COLLECTION
CONTAINER.
• Remove the stem from the vice and
drain off the oil inside it into the collec-
tion container.
SUSP - 212
RS4 125 Suspensions
CAUTION
ONLY FOR THE RIGHT STEM IT IS POSSIBLE TO REMOVE THE COMPLETE PISTON OPERAT-
ING AS FOLLOWS
• Undo and remove the piston retaining
screw on the foot of the fork
SUSP - 213
Suspensions RS4 125
MINGXING FORK
CAUTION
THE FOLLOWING PROCEDURES ARE FOR A SINGLE WHEEL CARRIER STANCHION/SLEEVE
ASSEMBLY, BUT ARE APPLICABLE TO BOTH.
• Fit the fork in the vice using the special
Teflon grips.
SUSP - 214
RS4 125 Suspensions
CAUTION
BEFORE PROCEEDING WITH THE FOLLOWING OPERATIONS GET A SUITABLE COLLECTION
CONTAINER.
• Remove the stem from the vice and
drain off the oil inside it into the collec-
tion container.
SUSP - 215
Suspensions RS4 125
SUSP - 216
RS4 125 Suspensions
PAIOLI FORKS
• Check the sliding surface for scorings and/or scratches. These scorings can be eliminated
by rubbing them with wet sandpaper (grain 1).
• If the scorings are deep, replace the stem.
• Use a dial gauge to check that the stem bending is below the limit value.
• If over the value, replace the stem.
SUSP - 217
Suspensions RS4 125
PAIOLI FORKS
CAUTION
ONLY FOR THE RIGHT STEM IT IS POSSIBLE TO INSTALL
THE COMPLETE PISTON OPERATING AS FOLLOWS
CAUTION
THE FOLLOWING PROCEDURES ARE FOR A SINGLE WHEEL CARRIER STANCHION/SLEEVE
ASSEMBLY, BUT ARE APPLICABLE TO BOTH.
• Insert the oil seal in the sleeve
SUSP - 218
RS4 125 Suspensions
Characteristic
Fork Paioli oil
390+/-5 ml (0.086 +/-0.0010 UK gal; 0.103 +/-
0.0013 US gal) (for each stem)
SUSP - 219
Suspensions RS4 125
MINGXING FORK
CAUTION
THE FOLLOWING PROCEDURES ARE FOR A SINGLE WHEEL CARRIER STANCHION/SLEEVE
ASSEMBLY, BUT ARE APPLICABLE TO BOTH.
• Insert the oil seal in the sleeve
SUSP - 220
RS4 125 Suspensions
Characteristic
Fork MingXing oil quantity
Right stem: 355+/-5 ml (0.0781+/-0.0011 UK gal;
0.0938 +/-0.0013 US gal)
Left stem: 360 +/-5 ml (0.0792+/-0.0792+/-0.0011 UK gal;
0.0951 +/-0.0013 US gal)
The following operations are described for the Paioli fork, but are identical for the operation with
the fork model Mingxing, except where specified.
SUSP - 221
Suspensions RS4 125
• Insert the stems holding pipe on the lower plate, in the clamps of the front headlamp and on
the upper plate.
• Insert the wheel pin through both sheaths to align the holes.
SUSP - 222
RS4 125 Suspensions
• Fit the front brake calliper and tighten the two fixing screws.
See also
Removing the
front wheel
Removal
SUSP - 223
Suspensions RS4 125
Rear
key:
SUSP - 224
RS4 125 Suspensions
9. Circlip d47
10.Bare rear wheel blue
11.Sprocket carrier
12.Bearing 25x47x14
13.Sealing ring 30x47x7
14.Int. spacer
15.Anti-vibration rubber buffer
16.Master link
17.Rear brake disc
18.TSPEI screw m8x20
19.Crown z=40
20.TE flanged screw m10x30
REAR WHEEL
pos. Description Type Quantity Torque Notes
1 Rear wheel axle nut M14 2 78 Nm (57.53 lbf ft) -
2 Rear disc fixing screw M6x20 6 12 Nm (8.85 lbf ft) -
3 Sprocket fixing screw TEF M8 6 25 Nm (18.44 lbf ft) -
4 Chain tensor fixing screw M8 2 12 Nm (8.85 lbf ft) Loctite 243
BEFORE CARRYING OUT THE FOLLOWING OPERATIONS AND IN ORDER TO AVOID BURNS,
ALLOW THE ENGINE AND SILENCER TO COOL OFF TO AMBIENT TEMPERATURE.
CAUTION
SUSP - 225
Suspensions RS4 125
UPON REMOVING, PAY ATTENTION NOT TO DAMAGE THE BRAKE HOSES, DISCS AND PADS.
CAUTION
TO REMOVE THE REAR WHEEL, GET THE APPROPRIATE REAR SERVICE STAND (OPTIONAL).
• Place the vehicle on its optional rear
stand.
• Remove the drive chain.
• Operating from both sides, remove the
two adjuster screws.
See also
Drive chain
SUSP - 226
RS4 125 Suspensions
• Slide the rear wheel completely off and check the mechanical components.
FLEXIBLE COUPLING
Check that the anti-vibration buffer is not damaged and/or excessively worn. Replace the buffer if nec-
essary.
Insert the anti-vibration buffer in the wheel hub.
Fit the entire final transmission unit on the wheel, manually rotate the crown gear to right and left and
check the clearance between the anti-vibration buffer and the hub. Replace the anti-vibration buffer if
excessive clearance is found.
SPROCKET
Check the toothing of the crown and the pinion. If excessive wear is found, replace: the crown, the pinion
and the drive chain.
CAUTION
REPLACE ALL THREE PARTS TO PREVENT EARLY WEAR OF NEW COMPONENTS.
SUSP - 227
Suspensions RS4 125
Shock absorbers
REAR SUSPENSION
pos. Description Type Quantity Torque Notes
1 Upper retainer M12 1 58 Nm (42.78 lbf ft) -
2 Lower retainer M12 1 58 Nm (42.78 lbf ft) Loctite 243
SUSP - 228
RS4 125 Suspensions
Removing
SUSP - 229
INDEX OF TOPICS
CHASSIS CHAS
RS4 125 Chassis
CHASSIS
pos. Description Type Quantity Torque Notes
1 Support coil fixing screw M8 2 20 Nm (14.75 lbf ft) -
2 TCEI screw M8 2 25 Nm (18.43 lbf ft) -
3 TCEI screw M10x45 4 50 Nm (36.88 lbf ft) -
4 TE screw M8x40 2 25 Nm (18.43 lbf ft) -
5 TE screw M6x16 2 12 Nm (8.85 lbf ft) Loctite 243
6 Right and left engine mount M10x16 2 38 Nm (28.02 lbf ft) Loctite 243
CHAS - 231
Chassis RS4 125
Swinging arm
SWINGARM
pos. Description Type Quantity Torque Notes
1 Swingarm to chassis adjustment nut M25x1.5 1 15 Nm (11.06 lbf ft) -
2 Swingarm pin nut M14 1 78 Nm (57.52 lbf ft) -
3 Chainguard fixing screw M 4.8x13 4 1 Nm (0.74 lbf ft) -
4 Chainguard fixing screw Self-tap. 2 - -
Removing
CHAS - 232
RS4 125 Chassis
See also
Removing the
rear wheel
Specific tooling
866714 Tools for the swingarm nut adjustment
• Lightly tap with a rubber hammer, slide the swingarm pin off the left side of the vehicle.
• If necessary, remove the rear mudguard and the chainguard.
Checking
CAUTION
CHECK THAT NO COMPONENT IS NOTICEABLY DISTORTED, DAMAGED, CRACKED AND/OR
DENTED.
REPLACE ALL DAMAGED COMPONENTS.
ROLLER CASINGS
Turn the roller casings manually; they must rotate continuously and silently.
There must be no axial clearance.
Replace the roller casings that present these problems.
Apply grease on the rollers.
GASKETS
Check that the gaskets are in good conditions; replace them if they show signs of damage or excessive
wear.
CHAS - 233
Chassis RS4 125
SWINGARM PIN
With a dial gauge check if the pin eccentricity ex-
ceeds the limit value. Otherwise, replace the pin.
Maximum pin eccentricity: 0.3 mm (0.01 in)
Installing
• To install the swingarm follow the operations described for removal in reverse order, being
careful to tighten the ring nuts, nuts and screws to the prescribed torque.
Pinion
LEVERS
pos. Description Type Quantity Torque Note
1 Pinion retainer nut M12x1.25 1 30 Nm (22.12 lb ft) Loctite 270
2 Pinion cover fixing screw TEF M5x16 2 4 Nm (2.95 lb ft) Maximum torque:
5.0 Nm (3.68 lb ft)
3 TCEI Screws pinion retainer M5x10 2 4 Nm (2.95 lb ft) Maximum torque:
5.0 Nm (3.68 lb ft) -
Loct. 270
CHAS - 234
RS4 125 Chassis
Removing
OPTION 01
OPTION 02
CHAS - 235
Chassis RS4 125
Installing
OPTION 01
CHAS - 236
RS4 125 Chassis
OPTION 02
CHAS - 237
Chassis RS4 125
See also
Adjusting
Drive chain
Removing
See also
Adjusting
inspection
Also check the following parts and make sure that the chain, pinion and crown do not present:
- Damaged rollers.
- Loose pins.
- Dry, rusty, flattened or jammed chain links.
- Excessive wear.
- Excessively worn or damaged pinion or crown teeth.
CAUTION
CHAS - 238
RS4 125 Chassis
IF THE CHAIN ROLLERS ARE DAMAGED AND / OR THE PINS ARE LOOSE, THE ENTIRE CHAIN
UNIT (PINION, CROWN AND CHAIN) SHOULD BE REPLACED.
LUBRICATE THE CHAIN ON A REGULAR BASIS, PARTICULARLY IF YOU DETECT DRY OR
RUSTY PARTS.
FLATTENED OR JAMMED CHAIN LINKS SHOULD BE LUBRICATED AND GOOD OPERATING
CONDITIONS RESTORED.
Installing
• Check the correct positioning of the chain on the pinion and the sprocket.
• Fit the chain with the two ends joined at a point between the pinion and the sprocket on the
lower branch of the chain.
• Join the two ends of the chain and fit the master link pins from the inside to the outside.
• Insert the plate on the pins.
Adjusting
To check clearance:
CHAS - 239
Chassis RS4 125
CHAS - 240
RS4 125 Chassis
Chain tensioner
STAND
pos. Description Type Quantity Torque Notes
1 Thin nut M10x1.25 1 10 Nm (7.38 lb ft) -
2 TCEI screw M8x30 2 25 Nm (18.43 lb ft) Loctite 243
3 TCEI screw M8x45 1 25 Nm (18.43 lb ft) -
4 TE Screws Flang. M5x25 2 3 Nm (2.21 lb ft) -
5 TE Screws M6x30 2 10 Nm (7.38 lb ft) -
Removing
CHAS - 241
Chassis RS4 125
Installing
CHAS - 242
RS4 125 Chassis
• Fit the roller on the chain tensioner plater after having assembled it complete with bearings
and spacer.
Stand
Side stand
CHAS - 243
Chassis RS4 125
Exhaust
EXHAUST
pos. Description Type Quantity Torque Notes
1 Drainage retainer M6x20 2 10 Nm (7.37 lbf ft) -
2 Footrest retainer M8x40 1 25 Nm (18.43 lbf ft) -
CHAS - 244
RS4 125 Chassis
See also
Side fairings
CHAS - 245
Chassis RS4 125
See also
Removing the tail pipe
CHAS - 246
INDEX OF TOPICS
FRONT CALLIPER
pos. Description Type Quantity Torque Notes
1 Front calliper fixing screw M10x60 2 50 Nm (36.87 lbf ft) -
Removal
• Undo the joint from the rear calliper after placing an appropriate container to collect the brake
fluid.
• Remove the speed sensor.
• It is now possible to remove the complete calliper
Installing
Removal
See also
Bleeding the braking system
Removal
Disc Inspection
Removal
Disc Inspection
Removal
• On the front brake calliper on the left hand side of the vehicle, undo and remove the two
brake calliper fastener screws.
• Measure the thickness of the brake pads. If one of the two falls under the serviceability limit,
replace them.
Removal
NOTE
THE PAD DISASSEMBLY AND INSTALLATION PROCEDURES FOR THE BRAKE CALLIPER ARE
THE SAME FOR BOTH THE A.J.P AND THE J.JUAN SYSTEM.
WARNING
IF THE BRAKE LEVER STARTS WITHOUT THE CALLIPER IT MAY BE NECESSARY TO CARRY
OUT BLEEDING.
• Remove the rear brake calliper.
• Press on the external pad in the direc-
tion of the arrow.
Front
Any air trapped in the hydraulic circuit acts as a cushion, absorbing much of the pressure applied by
the brake pump and minimising the braking power of the calliper.
The presence of air is signalled by the "sponginess" of the brake control and poor braking efficiency.
CONSIDERING THE DANGER FOR VEHICLE AND RIDER, IT IS STRICTLY NECESSARY, AFTER
REFITTING BRAKES AND RESTORING THE BREAKING SYSTEM TO THE REGULAR USE CON-
DITIONS, THAT THE HYDRAULIC CIRCUIT BE AIR PURGED.
NOTE
THE FOLLOWING OPERATIONS REFER TO ONLY ONE FRONT BRAKE CALLIPER BUT APPLY
TO BOTH CALLIPERS. THE VEHICLE MUST BE ON LEVEL GROUND TO BE PURGED. WHILE
PURGING THE HYDRAULIC SYSTEM, FILL THE RESERVOIR WITH THE NECESSARY QUANTITY
OF BRAKE FLUID. CHECK THAT, DURING THE OPERATION, THERE IS ALWAYS BRAKE FLUID
IN THE RESERVOIR.
• Remove the rubber protection cover from the bleed valve.
• Insert the transparent plastic pipe in the front brake calliper bleed valve and slide the other
end of this pipe in a container to collect the fluid.
• Remove the front brake fluid reservoir cap.
• Quickly press and release the front brake lever several times and then keep it fully pressed.
• Loosen the bleed valve 1/4 of a turn so that the brake fluid flows into the container. This will
release the tension on the brake lever and will make it reach the end of stroke.
• Close the bleed valve before the lever reaches its end of stroke.
• Repeat the operation until the fluid draining into the container is air-bubble free.
NOTE
WHILE PURGING THE HYDRAULIC SYSTEM, FILL THE RESERVOIR WITH THE NECESSARY
QUANTITY OF BRAKE FLUID. CHECK THAT, DURING THE OPERATION, THERE IS ALWAYS
BRAKE FLUID IN THE RESERVOIR.
Rear
Any air trapped in the hydraulic circuit acts as a cushion, absorbing much of the pressure applied by
the brake pump and minimising the braking power of the calliper.
The presence of air is signalled by the "sponginess" of the brake control and poor braking efficiency.
CAUTION
CONSIDERING THE DANGER FOR VEHICLE AND RIDER, IT IS STRICTLY NECESSARY, AFTER
REFITTING BRAKES AND RESTORING THE BRAKING SYSTEM TO THE REGULAR USE CON-
DITIONS, THAT THE HYDRAULIC CIRCUIT BE AIR PURGED. THE VEHICLE MUST BE ON LEVEL
GROUND TO BE PURGED. WHILE PURGING THE HYDRAULIC SYSTEM, FILL THE RESERVOIR
WITH THE NECESSARY QUANTITY OF BRAKE FLUID. CHECK THAT, DURING THE OPERATION,
THERE IS ALWAYS BRAKE FLUID IN THE RESERVOIR.
• Remove the rubber protection cover from the bleed valve.
• Insert the transparent plastic pipe in the rear brake calliper bleed valve and insert the other
end of this pipe into a container to collect the fluid.
• Remove the rear brake fluid reservoir cap.
• Quickly press and release the rear brake lever several times and then keep it fully pressed.
• Loosen the bleed valve 1/4 of a turn so that the brake fluid flows into the container. This will
release the tension on the brake lever and will make it reach the end of stroke.
• Close the bleed valve before the lever reaches its end of stroke.
• Repeat the operation until the fluid draining into the container is air-bubble free.
NOTE
WHILE PURGING THE HYDRAULIC SYSTEM, FILL THE RESERVOIR WITH THE NECESSARY
QUANTITY OF BRAKE FLUID CHECK THAT, DURING THE OPERATION, THERE IS ALWAYS
BRAKE FLUID IN THE RESERVOIR.
Rimozione
RADIATOR
pos. Description Type Quantity Torque Notes
1 Radiator retainer M6x25 2 10 Nm (7.37 lbf ft) -
2 Expansion tank support fixing screw M6x20 1 3.5-4 Nm (2.58-2.95 lbf -
ft)
WATER PUMP
pos. Description Type Quantity Torque Notes
1 Water pump fixing screw M5 3 5 - 6 Nm (3.68 - 4.42 lbf -
ft)
Circuit diagram
key:
1. Breather pipe
2. Radiator - expansion tank pipe
3. Cooling liquid reservoir
4. Cap
5. Clamp
6. Clamp D16-24x8
7. D10.1 clamp
8. Water radiator
9. Cap
10.TCEI screw M6x20
11.6.6x18x1.6 washer
12.Elastic plate M6
13.T-shaped bushing
14.TE flanged screw M6x25
15.Elastic plate M6
Electric fan
See also
Removing the
radiator
Coolant replacement
CAUTION
DO NOT USE YOUR VEHICLE IF THE COOLANT IS BELOW THE MINIMUM LEVEL.
CHECK THE COOLANT LEVEL PERIODICALLY OR AFTER LONG TRIPS.
• Remove the right fairing.
See also
Side fairings
Slide the pipe off and let the cooling liquid spill out,
by pouring it into a container of a suitable capacity.
CAUTION
Water pump
Removal
• Heat the clutch cover to facilitate extraction of the water pump spindle assembly;
• Support the clutch cover on a press
and with the specific tool "B", remove
the water pump shaft group, acting
from the external part to the internal
one.
Specific tooling
866380 tool description
Specific tooling
866380 tool description
Installing
CAUTION
ALWAYS REPLACE THE BEARINGS, THE OIL SEAL, AND THE SEALING RING, WHENEVER IT
IS NECESSARY TO REMOVE THE WATER PUMP.
• Place the new bearings on the press
and with the specific tool "B" push the
shaft until it stops;
Specific tooling
866380 tool description
Specific tooling
866380 tool description
Specific tooling
866380 tool description
Specific tooling
866380 tool description
See also
Removing the expansion
tank
Radiator installation
• Install the radiator following the removal operations but in reverse order.
• Fill the coolant tank with the recommended product.
• Check that the system does not show leaks.
See also
Side fairings
Coolant replacement
INSTALLATION
BODYWORK BODYW
Bodywork RS4 125
TANK
pos. Description Type Quantity Torque Notes
1 Rear tank fixing screw M8x40 1+1 25 Nm (18.44 lbf ft) -
2 Front tank fixing screw M6x35 1 10 Nm (7.37 lbf ft) -
3 Fastener screw M5x9 4 3 Nm (2.21 lbf ft) -
4 Tank cover fixing screw M5x9 4 3 Nm (2.21 lbf ft) -
BODYW - 274
RS4 125 Bodywork
Driving mirrors
Instrument panel
See also
Headlight fairing
BODYW - 275
Bodywork RS4 125
Headlight assy.
FRONT LIGHTS
pos. Description Type Quantity Torque Notes
1 Headlamp fixing screw M5x14 4 2.5 Nm (1.84 lbf ft) -
2 Self-tapping screw M5 1 1.5 Nm (1.11 lbf ft) -
BODYW - 276
RS4 125 Bodywork
See also
Headlight fairing
Headlight fairing
BODYW - 277
Bodywork RS4 125
BODYW - 278
RS4 125 Bodywork
Front wheelhouse
See also
Side fairings
BODYW - 279
Bodywork RS4 125
Taillight assy.
See also
Tail guard
BODYW - 280
RS4 125 Bodywork
Footrest
PASSENGER FOOTREST
The following procedures only refer to one foot-
rest, but they are applicable to both.
See also
Tail guard
Side fairings
BODYW - 281
Bodywork RS4 125
BODYW - 282
RS4 125 Bodywork
Air box
See also
Footrest
Fuel tank
Rear wheelhouse
BODYW - 283
Bodywork RS4 125
Rear mudguard
BODYW - 284
RS4 125 Bodywork
Lower cowl
See also
Side fairings
BODYW - 285
Bodywork RS4 125
Fuel tank
See also
BODYW - 286
RS4 125 Bodywork
Central part
Rear wheelhouse
BODYW - 287
Bodywork RS4 125
Radiator cover
BODYW - 288
RS4 125 Bodywork
Tail guard
BODYW - 289
INDEX OF TOPICS
PRE-DELIVERY PRE DE
RS4 125 Pre-delivery
Aesthetic inspection
- Paintwork
- Fitting of Plastic Parts
- Scratches
- Dirt
Electrical system
- Main switch
- Headlamps: high beam lights, low beam lights, tail lights (front and rear) and their warning lights
- Headlight adjustment according to regulations in force
- Front and rear stop light switches and their bulbs
- Turn indicators and their warning lights
- Instrument panel lights
- Instrument panel: fuel and temperature indicator (if present)
- Instrument panel warning lights
PRE DE - 291
Pre-delivery RS4 125
- Horn
- Electric starter
- Engine stop via emergency stop switch and side stand
- Helmet compartment electrical opening switch (if present)
- Through the diagnosis tool, check that the last mapping version is present in the control unit/s and, if
required, program the control unit/s again: consult the technical service website to know about available
upgrades and details regarding the operation.
CAUTION
UPON INSTALLING THE BATTERY, ATTACH THE POSITIVE LEAD FIRST AND THEN THE NEG-
ATIVE ONE, AND PERFORM THE REVERSE OPERATION UPON REMOVAL.
WARNING
NEVER USE FUSES WITH A CAPACITY HIGHER THAN THE RECOMMENDED CAPACITY. USING
A FUSE OF UNSUITABLE RATING MAY SERIOUSLY DAMAGE THE VEHICLE OR EVEN CAUSE
A FIRE.
Levels check
PRE DE - 292
RS4 125 Pre-delivery
Road test
- Cold start
- Instrument panel operation
- Response to throttle control
- Stability when accelerating and braking
- Front and rear brake efficiency
- Front and rear suspension efficiency
- Abnormal noise
Static test
Static check after test drive:
- Restarting when warmed up
- Starter operation (if present)
- Minimum holding (turning the handlebar)
- Uniform turning of the steering
- Possible leaks
- Radiator electric fan operation (if present)
Functional inspection
- Hydraulic braking system
- Stroke of brake and clutch levers (if present)
- Clutch - Check for correct operation
- Engine - Check for correct general operation and absence of abnormal noise
- Other
- Documentation check:
- Chassis and engine numbers check
- Supplied tools check
- License plate fitting
- Locks checking
- Tyre pressure check
- Installation of mirrors and any possible accessories
PRE DE - 293
Pre-delivery RS4 125
PRE DE - 294
RS4 125 Pre-delivery
• Access the Quick Shift connector by lifting the tank, the connector is placed, as shown in
the figure, internally on the left side of the chassis.
• Connect the two cables.
PRE DE - 295
A
Air filter: 55
B
Battery: 98, 108
Brake: 249, 251–254, 256, 259, 260
Brake calliper: 249, 251
Brake disc: 252, 253
Brake fluid: 259
Brake pads: 254, 256
Brake pump: 260
Bulbs:
C
Chain: 184, 226, 238, 241
Chain tensioner: 184, 241
Clutch: 62, 148, 149, 151, 153–155, 159
Coil: 120
Connectors: 123
coolant: 127, 265, 272
Coolant: 127, 265, 272
Countershaft: 158, 159, 166, 168
Crankcase: 42, 140, 157, 160, 164, 167
Crankshaft: 42, 165
Cylinder: 42, 161, 175, 183, 185, 190, 191
D
Desmodromic drum: 141
Drive chain: 238
E
ECU: 124
Electric fan: 122, 265
Electrical system: 11, 64, 65, 291
Engine oil: 52
Engine temperature sensor: 115
Exhaust: 244, 246
Exhaust manifold: 246
F
Fairings: 127, 245, 266, 272, 279, 281, 285
Fork: 210, 211, 218, 221
Front wheel: 207, 209, 211, 223
Fuel: 119, 127, 199, 200, 283, 286
Fuel pump: 119, 199
Fuses: 108
G
Gearbox oil: 55
H
Handlebar: 210
Head cover: 172
Headlight: 275–277
Horn: 105
I
Identification: 9
Instrument panel: 275
L
License plate holder: 282
M
Magneto flywheel: 145, 147, 162
Maintenance: 7, 50
Mirrors: 275
Mudguard: 211, 284
O
Oil filter: 54
P
Primary shaft: 140
R
Radiator: 127, 265, 269, 288
Rear wheel: 225, 227, 228, 233
Recommended products: 43
S
Scheduled maintenance:
Shock absorbers: 228
Side fairings: 281
Side stand: 122, 243
Side stand sensor: 122
Spark plug: 51
Speed sensor: 113
Stand: 122, 243
Start-up: 103
Starter motor: 142, 143, 174
T
Tank: 127, 200, 270, 271, 283, 286
Throttle body: 202
Transmission: 11
Tyres: 12
V
Voltage regulator: 102
W
Warning lights:
Water pump: 266
Windshield:
Wiring diagram: 92