CHAPTER 4
ENGINE
SEAT, FUEL TANK
AND SIDE COVERS
................................. 4-1
EXHAUST PIPE AND SILENCER
............ 4-2
RADIATOR
............................................... 4-4
CARBURETOR
......................................... 4-7
CAMSHAFTS
.......................................... 4-20
CYLINDER HEAD
................................... 4-29
VALVES AND VALVE SPRINGS
........... 4-33
CYLINDER AND PISTON
....................... 4-42
CLUTCH
.................................................. 4-49
OIL FILTER ELEMENT, WATER PUMP
AND RIGHT CRANKCASE COVER
...... 4-56
BALANCER
............................................ 4-63
OIL PUMP
............................................... 4-66
KICK SHAFT AND SHIFT SHAFT
......... 4-71
CDI MAGNETO
....................................... 4-78
ENGINE REMOVAL
................................ 4-82
CRANKCASE AND CRANKSHAFT
....... 4-87
TRANSMISSION, SHIFT CAM
AND SHIFT FORK
.................................. 4-96
CHAPTER 5
CHASSIS
FRONT WHEEL AND REAR WHEEL
...... 5-1
FRONT BRAKE AND REAR BRAKE
.... 5-11
FRONT FORK
......................................... 5-28
HANDLEBAR
.......................................... 5-41
STEERING
.............................................. 5-47
SWINGARM
............................................ 5-53
REAR SHOCK ABSORBER
................... 5-60
1 - 2
GEN
INFO
MACHINE IDENTIFICATION
EC120001
MACHINE IDENTIFICATION
There are two significant reasons for knowing
the serial number of your machine:
1. When ordering parts, you can give the
number to your Yamaha dealer for posi-
tive identification of the model you own.
2. If your machine is stolen, the authorities
will need the number to search for and
identify your machine.
EC121001
VEHICLE IDENTIFICATION NUMBER
The vehicle identification number
1
is
stamped on the right of the steering head pipe.
EC123001
ENGINE SERIAL NUMBER
The engine serial number
1
is stamped into
the elevated part of the right-side of the
engine.
EC124000
MODEL LABEL
The model label
1
is affixed to the frame
under the rider’s seat. This information will be
needed to order spare parts.
GEN
INFO
1 - 8
SPECIAL TOOLS
YU-33975, 90890-01403 Steering nut wrench
This tool is used when tighten the steering ring nut to
specification.YU-33975 90890-01403
YM-1423, 90890-01423 Damper rod holder
Use this tool to remove and install the damper rod.YM-1423 90890-01423
YM-01442, 90890-01442 Fork seal driver
This tool is used when install the fork oil seal.YM-01442 90890-01442
YU-3112-C, 90890-03112 Pocket tester
Use this tool to inspect the coil resistance, output
voltage and amperage.YU-3112-C 90890-03112
YU-08036-B
90890-03113Inductive tachometer
Engine tachometer
This tool is needed for observing engine rpm.YU-08036-B 90890-03113
YM-33277-A, 90890-03141 Timing light
This tool is necessary for checking ignition timing.YM-33277-A 90890-03141
YM-04019, 90890-04019 Valve spring compressor
This tool is needed to remove and install the valve
assemblies.YM-04019 90890-04019
YM-91042, 90890-04086 Clutch holding tool
This tool is used to hold the clutch when removing or
installing the clutch boss securing nut.YM-91042 90890-04086
YM-4111, 90890-04111
YM-4116, 90890-04116Valve guide remover
Intake 4.0 mm (0.16 in)
Exhaust 4.5 mm (0.18 in)
This tool is needed to remove and install the valve
guide.YM-4111
YM-411690890-04111
90890-04116
Part number Tool name/How to use Illustration
GEN
INFO
1 - 18
TORQUE-CHECK POINTS
TORQUE-CHECK POINTS
Frame construction
Combined seat and fuel tank
Exhaust system
Engine mounting
Steering Steering stem to
handlebar
Suspension Front Steering stem to front
fork
Rear For link type
Rear Installation of rear
shock absorber
Rear Installation of swing-
arm
Wheel Installation of wheel Front
Rear
Brake Front
Rear
Fuel systemFrame to rear frame
Fuel tank to frame
Silencer to rear frame
Frame to engine
Steering stem to frame
Steering stem to upper bracket
Upper bracket to handlebar
Front fork to upper bracket
Front fork to lower bracket
Assembly of links
Link to frame
Link to rear shock absorber
Link to swingarm
Rear shock absorber to frame
Tightening of pivot shaft
Tightening of wheel axle
Tightening of axle holder
Tightening of wheel axle
Wheel to rear wheel sprocket
Brake caliper to front fork
Brake disc to wheel
Tightening of union bolt
Brake master cylinder to handlebar
Tightening of bleed screw
Brake disc to wheel
Tightening of union bolt
Brake master cylinder to frame
Tightening of bleed screw
Fuel tank to fuel cock
NOTE:
Concerning the tightening torque, refer to
“MAINTENANCE SPECIFICATIONS” section
in the CHAPTER 2.
SPEC
2 - 12
MAINTENANCE SPECIFICATIONS
CHASSIS
Item Standard Limit
Steering system:
Steering bearing type Taper roller bearing ----
Front suspension: USA, CDN EUROPE AUS, NZ, ZA
Front fork travel 300 mm (11.8 in)¬¬
Fork spring free length 460 mm (18.1 in)¬¬
Spring rate, STD K = 4.31 N/mm
(0.44 kg/mm,
24.6 lb/in)K = 4.12 N/mm
(0.42 kg/mm,
23.5 lb/in)K = 4.02 N/mm
(0.41 kg/mm,
23 lb/in)
Optional spring/spacer Yes¬¬
Oil capacity 568 cm
3
(20.0 lmp oz,
19.2 US oz) 578 cm3
(20.3 lmp oz,
19.5 US oz) 568 cm3
(20.0 lmp oz,
19.2 US oz)
Oil level 140 mm (5.51 in) 130 mm (5.12 in) 140 mm (5.51 in)
(From top of outer tube with inner
tube and damper rod fully com-
pressed without spring.)80 ~ 150 mm
(3.15 ~ 5.91 in)¬¬
Oil grade Suspension oil
“01”¬¬
Inner tube outer diameter 46 mm (1.81 in)¬¬
Front fork top end 7 mm (0.28 in) 8 mm (0.31 in) 10.5 mm (0.41 in)
Rear suspension: USA, CDN EUROPE AUS, NZ, ZA
Shock absorber travel 132 mm (5.20 in)¬¬
Spring free length260 mm (10.24 in)¬¬
Fitting length240.5 mm (9.47 in)247 mm (9.72 in)243.5 mm (9.59 in)
(9.47 ~ 10.18 in)¬¬
Spring rate, STD K = 47.0 N/mm
(4.80 kg/mm,
268.8 lb/in)¬¬
Optional spring Yes¬¬
Enclosed gas pressure
1,000 kPa
(10 kg/cm2, 142 psi)
¬¬
Swingarm:
Swingarm free play limit
End ---- 1.0 mm
(0.04 in)
SPEC
2 - 14
MAINTENANCE SPECIFICATIONS
NOTE:
1. First, tighten the steering nut approximately 38 Nm (3.8 m • kg, 27 ft • lb) by using the steering
nut wrench, then loosen the steering nut one turn.
2. Retighten the steering nut 7 Nm (0.7 m • kg, 5.1 ft • lb).Part to be tightened Thread size Q’tyTightening torque
Nm m·kg ft·lb
Upper bracket and outer tube M8 ´ 1.25 4 23 2.3 17
Lower bracket and outer tube M8 ´ 1.25 4 20 2.0 14
Upper bracket and steering stem M24 ´ 1.0 1 145 14.5 105
Handlebar holder and upper bracket M8 ´ 1.25 4 28 2.8 20
Steering stem and steering ring nut M28 ´ 1.0 1 Refer to NOTE.
Front fork and front fork cap bolt M48 ´ 1.0 2 30 3.0 22
Front fork and base valve M30 ´ 1.0 2 55 5.5 40
Front fork cap bolt and damper rod M12 ´ 1.25 2 29 2.9 21
Front fork bleed screw and front fork cap bolt M5 ´ 0.8 2 1 0.1 0.7
Front fork and front fork protector M6 ´ 1.0 6 10 1.0 7.2
Meter cable holder and front fork protector M5 ´ 0.8 2 4 0.4 2.9
Front fork and brake hose guide M5 ´ 0.8 2 4 0.4 2.9
Front fork and brake hose holder M6 ´ 1.0 2 10 1.0 7.2
Front fork and brake hose cover (M8) M8 ´ 1.25 1 16 1.6 11
(M6) M6 ´ 1.0 1 7 0.7 5.1
Throttle grip cap M5 ´ 0.8 2 4 0.4 2.9
Front brake master cylinder M6 ´ 1.0 2 9 0.9 6.5
Brake lever mounting bolt M6 ´ 1.0 1 6 0.6 4.3
Brake lever mounting nut M6 ´ 1.0 1 6 0.6 4.3
Brake lever position locknut M6 ´ 1.0 1 5 0.5 3.6
Front brake hose guide M5 ´ 0.8 2 4 0.4 2.9
Clutch lever holder M5 ´ 0.8 2 4 0.4 2.9
Clutch lever mounting bolt M6 ´ 1.0 1 2 0.2 1.4
Decompression lever holder M5 ´ 0.8 2 4 0.4 2.9
Light switch M4 ´ 0.7 2 2 0.2 1.4
Front brake master cylinder cap M4 ´ 0.7 2 2 0.2 1.4
Front brake hose union bolt M10 ´ 1.25 2 30 3.0 22
Front brake caliper M8 ´ 1.25 2 23 2.3 17
Pad pin plug M10 ´ 1.0 2 3 0.3 2.2
Front brake caliper and pad pin M10 ´ 1.0 1 18 1.8 13
Rear brake caliper and pad pin M10 ´ 1.0 1 18 1.8 13
Brake caliper and bleed screw M8 ´ 1.25 2 6 0.6 4.3
Front wheel axle and axle nut M16 ´ 1.5 1 105 10.5 75
Front wheel axle holder M8 ´ 1.25 4 23 2.3 17
Front brake disc M6 ´ 1.0 6 12 1.2 8.7
2 - 19
SPEC
CABLE ROUTING DIAGRAM
EC240000
CABLE ROUTING DIAGRAM
1
Hose guide
2
Brake hose
3
Voltage regulator
4
Light switch lead
5
Fuel tank breather hose
6
Clamp
7
Oil tank breather hose
8
Engine stop switch lead
9
Sub-wire harness
0
Taillight lead
A
Throttle position sensor lead
B
Neutral switch lead
C
Oil hose
D
Cylinder head breather hose
E
CDI magneto lead
F
Clutch cable
G
Cable guide
H
Carburetor breather hose
I
Carburetor overflow hose
J
Coolant reservoir breather hose
K
Decompression cable
L
CDI unit lead
M
Ignition coil lead
N
Voltage regulator lead
Pass the fuel tank breather hose
behind handlebar, then insert it
into the steering stem hole.
õ
Pass the decompression cable,
engine stop switch lead and light
switch lead under where the oil
hose is attached.
‚
Pass the voltage regulator lead,
engine stop switch lead and light
switch lead over the radiator
hose.
ë
Fasten the engine stop switch
lead and ignition coil lead of the
sub-wire harness.
ä
Fasten the sub-wire harness
and engine stop switch lead.
ì
Pass the cylinder head breather
hose along the right side of the
oil tank breather hose.
í
Fasten the sub-wire harness
and engine stop switch lead in
front of the upper engine brack-
ets.
î
Fasten the sub-wire harness.
é
Pass the sub-wire harness
between the upper engine
brackets.
ï
Fasten the sub-wire harness.
ð
Fasten the throttle position sen-
sor lead.
3 - 3
INSP
ADJ
MAINTENANCE INTERVALS
* marked : For USAFRONT FORK OIL SEAL AND DUST
SEAL
Clean and lube
c
c
Lithium base grease
REAR SHOCK ABSORBER
Inspect and adjust
Lube
Retighten
c
c
c
c
c c Molybdenum disulfide
grease
CHAIN GUARD AND ROLLERS
Inspect
c c
SWINGARM
Inspect and retighten
c c
RELAY ARM, CONNECTING ROD
Inspect and lube
c c Molybdenum disulfide
grease
STEERING HEAD
Inspect free play and retighten
Clean and lube
Replace bearing
c c
c
c Lithium base grease
TIRE, WHEELS
Inspect air pressure, wheel run-out,
tire wear and spoke looseness
Retighten sprocket bolt
Inspect bearings
Replace bearings
Lubricate
c
c
c
c
c
c
c
Lithium base grease
THROTTLE, CONTROL CABLE
Check routing and connection
Lubricate
c
c
c
c Yamaha cable lube or
SAE 10W-30 motor oil ItemAfter
break-inEvery
race
Every
third race
or
500 km
(300 mi)Every
fifth race
or
1,000 km
(600 mi)
As re-
quiredRemarks