Page 24 of 287

CHAPTER 4
ENGINE
CARBURETOR
......................................... 4-1
CYLINDER HEAD
..................................... 4-8
CAMSHAFT AND ROCKER ARMS
....... 4-13
VALVES AND VALVE SPRINGS
........... 4-16
CYLINDER AND PISTON
....................... 4-21
CLUTCH
.................................................. 4-27
KICK AXLE
............................................. 4-33
SHIFT SHAFT
......................................... 4-34
OIL PUMP
............................................... 4-36
CDI MAGNETO
....................................... 4-39
CRANKCASE AND CRANKSHAFT
....... 4-41
SHIFT FORK, SHIFT CAM AND
TRANSMISSION
..................................... 4-44
CHAPTER 5
CHASSIS
FRONT WHEEL AND REAR WHEEL
...... 5-1
FRONT FORK
........................................... 5-6
HANDLEBAR
............................................ 5-9
STEERING
.............................................. 5-10
SWINGARM
............................................ 5-11
CHAPTER 6
ELECTRICAL
ELECTRICAL COMPONENTS AND
WIRING DIAGRAM
................................... 6-1
IGNITION SYSTEM
................................... 6-2
CARBURETOR HEATING SYSTEM
........ 6-6
MAINTENANCE RECORD
....................... 6-9
Page 37 of 287

GEN
INFO
1 - 7
SPECIAL TOOLS
YM-01326, 90890-01326 T-handle
This tool is used for holding the damper rod holder
when removing or installing the damper rod holder.YM-01326 90890-01326
YM-1369, 90890-01186 Fork seal driver attachment
This tool is used to installing the oil seal.YM-1369 90890-01186
YM-08035, 90890-01311 Valve adjusting tool
This tool is necessary for adjusting valve clearance.YM-08035 90890-01311
YM-33963, 90890-01184 Fork seal driver weight
This tool is used to installing the oil seal.YM-33963 90890-01184
YM-34487
90890-06754Dynamic spark tester
Ignition checker
This instrument is necessary for checking the ignition
system components.YM-34487 90890-06754
YM-33975, 90890-01403 Ring nut wrench
This tool is used when tighten the steering ring nut to
specification.YM-33975 90890-01403
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
YS-01880, 90890-01701 Sheave holder
This tool is used for when loosening or tightening the
flywheel magneto securing nut.YS-01880 90890-01701
YU-33270, 90890-01362 Flywheel puller
This tool is used to remove the rotor.YU-33270 90890-01362
Part number Tool name/How to use Illustration
Page 66 of 287

SPEC
2 - 11
EC212201
CHASSIS
Item Standard Limit
Steering system:
Steering bearing type Taper roller bearing
Angular bearing----
Front suspension:
Front fork travel 110 mm (4.33 in) ----
Fork spring free length 425.1 mm (16.74 in) 417 mm (16.4 in)
Fork spring fitting length 415.1 mm (16.34 in) ----
Spring rate, STD K = 3.4 N/mm
(0.35 kg/mm, 19.41 lb/in)----
Optional spring/spacer No ----
Oil capacity 64 cm
3
(2.26 lmp oz, 2.16 US oz) ----
Oil level 185 mm (7.28 in) ----
Oil grade Fork oil 15W or equivalent ----
Rear suspension:
Shock absorber travel 48 mm (1.89 in) ----
Spring free length 169 mm (6.65 in) ----
Fitting length 165 mm (6.5 in) ----
Spring rate, STD K = 45.6 N/mm
(4.6 kg/mm, 260 lb/in)----
Optional spring No ----
Enclosed gas pressure 2,000 kPa
(20 kg/cm
2
, 290 psi)----
Swingarm:
Swingarm free play limit
End ---- 1.0 mm (0.04 in)
Side clearance ---- 0.3 mm (0.01 in)
Wheel:
Front wheel type Spoke wheel ----
Rear wheel type Spoke wheel ----
Front rim size/Material 14
´
1.40/Steel ----
Rear rim size/Material 12
´
1.60/Steel ----
Rim runout limit:
Radial ---- 2.0 mm (0.08 in)
Lateral ---- 2.0 mm (0.08 in)
Drive chain:
Type/Manufacturer 420/DAIDO ----
Number of links 86 links ----
Chain slack 40 ~ 53 mm (1.6 ~ 2.1 in) ----
Chain length (10 links) ---- 152.5 mm
(6.00 in)
MAINTENANCE SPECIFICATIONS
Page 68 of 287

SPEC
2 - 13
HINWEIS:NOTE:
1. First, tighten the ring nut approximately 38 Nm (3.8 m • kg, 27 ft • lb) by using the ring nut
wrench, then loosen the ring nut completely.
2. Retighten the ring nut 1 Nm (0.1 m • kg, 0.7 ft • lb).Part to be tightened Thread size Q’tyTightening torque
Nm m•kg ft•lb
Engine mounting:
Engine and frame (front-upper) M8 ´ 1.25 1 30 3.0 22
Engine and frame (rear-upper) M8 ´ 1.25 1 26 2.6 19
Engine and frame (rear-lower) M10 ´ 1.25 1 40 4.0 29
Pivot shaft and nut M10 ´ 1.25 1 30 3.0 22
Handle crown and steering shaft M10 ´ 1.25 1 40 4.0 29
Front fork cap bolt M20 ´ 1.0 2 40 4.0 29
Handle crown and handlebar holder (lower) M10 ´ 1.25 2 40 4.0 29
Handlebar holder (upper) M6 ´ 1.0 4 13 1.3 9.4
Front brake cable holder and front fork M6 ´ 1.0 2 7 0.7 5.1
Steering ring nut M25 1 Refer to NOTE.
Fuel tank and fuel cock M6 ´ 1.0 2 7 0.7 5.1
Fuel tank and frame M6 ´ 1.0 2 7 0.7 5.1
Grab bar and frame M6 ´ 1.0 4 13 1.3 9.4
Front brake camshaft lever and camshaft M6 ´ 1.0 1 7 0.7 5.1
Rear brake camshaft lever and camshaft M6 ´ 1.0 1 7 0.7 5.1
Front wheel axle nut M10 ´ 1.25 1 35 3.5 25
Rear brake shoe plate tension bar M8 ´ 1.25 2 26 2.6 19
Wheel drive hub and driven sprocket M8 ´ 1.25 4 25 2.5 18
Rear wheel axle nut M12 ´ 1.25 1 60 6.0 43
Footrest and frame M8 ´ 1.25 2 30 3.0 22
MAINTENANCE SPECIFICATIONS
Page 108 of 287

3 - 1
INSP
ADJ
MAINTENANCE INTERVALS/
PERIODIC MAINTENANCE AND LUBRICATION
EC300000
REGULAR INSPECTION AND ADJUSTMENTS
EC310022
MAINTENANCE INTERVALS
The following schedule is intended as a general guide to maintenance and lubrication. Bear in mind
that such factors as weather, terrain, geographical location, and individual usage will alter the
required maintenance and lubrication intervals. If you are a doubt as to what intervals to follow in
maintaining and lubricating your machine, consult your Yamaha dealer.
PERIODIC MAINTENANCE AND LUBRICATION
Dealer
NoteItem Checks and maintenance jobsInitial Every
10 hours
(1 month)60 hours
(6 months)120 hours
(12 months)
* Fuel lineCheck fuel hoses for cracks or damage.
Replace if necessary.
Spark plugCheck condition.
Clean, regap or replace if necessary.
* ValvesCheck valve clearance.
Adjust if necessary.
Air filter Clean or replace if necessary.
* CarburetorCheck engine idling speed and starter operation.
Adjust if necessary.
Exhaust systemsCheck for leakage.
Retighten if necessary.
Replace gasket if necessary.
Engine oilCheck oil level and vehicle for oil leakage.
Correct if necessary.
Change. (Warm engine before draining.)
ClutchCheck operation.
Adjust or replace cable.
* Front brakeCheck operation.
Adjust brake lever free play and replace brake
shoes if necessary.Every ride
* Rear brakeCheck operation.
Adjust brake pedal free play and replace brake
shoes if necessary.Every ride
* WheelsCheck balance, runout, spoke tightness and for
damage.
Tighten spokes and rebalance, replace if
necessary.
* TiresCheck tread depth and for damage.
Replace if necessary.
Check air pressure.
Correct if necessary.
* Wheel bearingsCheck bearing for looseness or damage.
Replace if necessary.
* SwingarmCheck swingarm pivoting point for play.
Correct if necessary.
Lubricate with lithium soap base grease.
Drive chainCheck chain slack.
Adjust if necessary. Make sure that the rear wheel
is properly aligned.
Clean and lubricate.Every ride
* Steering bearingsCheck bearing play and steering for roughness.
Correct accordingly.
Lubricate with lithium soap base grease every 120
hours.
3
3
Page 138 of 287
3 - 15
INSP
ADJSPOKES INSPECTION AND TIGHTENING/WHEEL INSPECTION/
STEERING HEAD INSPECTION AND ADJUSTMENT
EC36S002
SPOKES INSPECTION AND TIGHTENING
1. Inspect:
lSpokes 1
Bend/damage ® Replace.
Loose spoke ® Retighten.
2. Tighten:
lSpokes
NOTE:
Be sure to retighten these spokes before and
after break-in. After a practice or a race check
spokes for looseness.
T R..2.5 Nm (0.25 m · kg, 1.8 ft · lb)
EC36T000
WHEEL INSPECTION
1. Inspect:
lWheel runout
Elevate the wheel and turn it.
Abnormal runout ® Replace.
2. Inspect:
lBearing free play
Exist play ® Replace.
EC36U012
STEERING HEAD INSPECTION AND
ADJUSTMENT
1. Elevate the front wheel by placing a suit-
able stand under the engine.
2. Check:
lSteering shaft
Grasp the bottom of the forks and gen-
tly rock the fork assembly back and
forth.
Free play ® Adjust steering head.