wheel YAMAHA TTR90 2003 User Guide

3 - 13
INSP
ADJFRONT FORK INSPECTION/REAR SHOCK ABSORBER INSPECTION/
REAR SHOCK ABSORBER SPRING PRELOAD ADJUSTMENT
Tighten the wheel axle nut while pushing
down the drive chain.
T R..
Axle nut:
60 Nm (6.0 m • kg, 43 ft • lb)
Tighten the locknuts.
T R..
Locknut:
7 Nm (0.7 m • kg, 5.1 ft • lb)
EC36C000
FRONT FORK INSPECTION
1. Inspect:
Front fork smooth action
Operate the front brake and stroke the
front fork.
Unsmooth action/oil leakage → Repair
or replace.
EC36K000
REAR SHOCK ABSORBER INSPECTION
1. Inspect:
Swingarm smooth action
Abnormal noise/unsmooth action →
Grease the pivoting points or repair the
pivoting points.
Damage/oil leakage → Replace.
REAR SHOCK ABSORBER SPRING
PRELOAD ADJUSTMENT
1. Elevate the rear wheel by placing the
suitable stand under the engine.
2. Remove:
Rear shock absorber
Refer to “SWINGARM” section in the
CHAPTER 5.
3. Remove:
Spring guide 1
NOTE:
While compressing the spring, remove the
spring guide.

3 - 15
INSP
ADJSPOKES INSPECTION AND TIGHTENING/WHEEL INSPECTION/
STEERING HEAD INSPECTION AND ADJUSTMENT
SPOKES INSPECTION AND TIGHTENING
1. Inspect:
Spokes 1
Bend/damage → Replace.
Loose spoke → Retighten.
2. Tighten:
Spokes
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 Nm (0.2 m · kg, 1.4 ft · lb)
EC36T000
WHEEL INSPECTION
1. Inspect:
Wheel runout
Elevate the wheel and turn it.
Abnormal runout → Replace.
2. Inspect:
Bearing free play
Exist play → Replace.
STEERING HEAD INSPECTION AND
ADJUSTMENT
1. Elevate the front wheel by placing a suit-
able stand under the engine.
2. Check:
Steering shaft
Grasp the bottom of the forks and gen-
tly rock the fork assembly back and
forth.
Free play → Adjust steering head.

4 - 33
ENGKICK AXLE
KICK AXLE
Extent of removal:1 Kick axle removal2 Kick axle disassembly
Extent of removal Order Part name Q’ty Remarks
KICK AXLE REMOVAL AND
DISASSEMBLY
Preparation for removal Crankcase cover (right) Refer to “CLUTCH” section.
1 Kick axle assembly 1
2 Circlip 2
3 Spring cover 1
4 Torsion spring 1
5 Spring guide 1
6 Circlip 1
7 Ratchet wheel 1
8 Clip 1
9 Circlip 1
10 Washer/wave washer 1/1
11 Kick gear 1
12Kick axle
1
1
2

4 - 39
ENGCDI MAGNETO AND STARTER CLUTCH
CDI MAGNETO AND STARTER CLUTCH
Extent of removal:1 Pickup coil/stator removal2 Rotor removal
3 Starter clutch/wheel gear removal
Extent of removal Order Part name Q’ty Remarks
CDI MAGNETO AND STATOR
REMOVAL
Preparation for removal Fuel tank
Crankcase cover (left) Refer to “CLUTCH” section.
1 CDI magneto coupler 1
2 Pickup coil/stator assembly 1
3 Rotor nut 1
Use special tool.
Refer to “REMOVAL POINTS”. 4 Rotor 1
5 Woodruff key 1
6 Shaft 1
7 Idler gear 1
8 Starter clutch/wheel gear 1/1
1
2
3

4 - 40
ENGCDI MAGNETO AND STARTER CLUTCH
REMOVAL POINTS
Rotor
1. Remove:
Rotor nut 1
Washer 2
NOTE:
Loosen the rotor nut while holding the rotor
with sheave holder 3.
Do not allow the sheave holder to touch the
projection on the rotor.
Sheave holder:
YS-1880-A/90890-01701
2. Remove:
Rotor 1
Woodruff key
NOTE:
Use the flywheel puller 2.
Center the flywheel puller over the rotor.
Make sure after installing the holding bolts
that the clearance between the flywheel
puller and the rotor is the same everywhere.
If necessary, one holding bolt may be turned
out slightly to adjust the flywheel puller’s
position.
CAUTION:
Cover the crankshaft end with the box
wrench for protection.
Flywheel puller:
YU-33270-B/90890-01362

4 - 41
ENG
INSPECTION
Starter clutch
1. Inspect:
Starter idle gear teeth a
Starter drive gear teeth b
Starter wheel gear teeth c
Burrs/chips/roughness/wear →
Replace.
2. Check:
Starter clutch operation
Push the dowel pins to the arrow direc-
tion.
Unsmooth operation → Replace.
Checking steps:
Hold the starter clutch.
When turning the starter wheel gear clock-
wise Å, the starter clutch and the starter
wheel gear should be engaged.
If not, the starter clutch is faulty. Replace
it.
When turning the starter wheel gear coun-
terclockwise ı, it should turn freely.
If not, the starter clutch is faulty. Replace
it.
ı
Å
ASSEMBLY AND INSTALLATION
Starter clutch
1. Install:
Starter clutch 1
1T R..14 Nm (1.4 m · kg, 10 ft · lb)
2. Unloosen the starter clutch assembly by
using the center punch.
CDI MAGNETO AND STARTER CLUTCH

4 - 42
ENGCDI MAGNETO AND STARTER CLUTCH
3. Install:
Spring 1
Spring cap 2
Pin 3
4. Install:
Shim 1
Starter wheel gear 2
Starter idle gear 3
Shaft 4
NOTE:
Apply the molybdenum disulfide oil on the
starter wheel gear inner circumference.
Apply the engine oil on the starter idle gear
inner circumference and on the shaft outer
circumference.
12
3
123
5. Install:
Woodruff key 1
Rotor 2
NOTE:
Clean the tapered portion of the crankshaft
and the magneto hub.
When installing the magneto rotor, make
sure the woodruff key is properly seated in
the key way of the crankshaft.
6. Tighten:
Nut (magneto) 1
NOTE:
Tighten the nut (magneto) 1 while holding the
magneto 2 with a sheave holder 3.
7. Install:
Crankcase cover (left)
NOTE:
Pass the starter motor lead 1 and neutral
switch lead 2 into the crankcase cover
groove as shown.
Fasten the starter motor lead with the clamp 3.
Sheave holder:
YS-1880-A/90890-01701
T R..48 Nm (4.8 m · kg, 35 ft · lb)
2
1
1
3

4 - 47
ENGSHIFT FORK, SHIFT CAM AND TRANSMISSION
Extent of removal Order Part name Q’ty Remarks
10 3rd pinion gear 1
11 Main axle 1
12 Circlip 1
13 Washer 1
14 Collar 1
15 1st wheel gear 1
16 3rd wheel gear 1
17 Circlip 1
18 Washer 1
19 2nd wheel gear 1
20 Drive axle 1
2
3

5 - 1
CHAS

EC500000
CHASSIS
FRONT WHEEL AND REAR WHEEL
FRONT WHEEL AND FRONT BRAKE
FRONT WHEEL AND REAR WHEEL
Extent of removal:
1
Front wheel removal
2
Wheel bearing removal
3
Brake shoe plate assembly removal and disassembly
Extent of removal Order Part name Q’ty Remarks
FRONT WHEEL REMOVAL
WARNING

Support the machine securely so there is no
danger of it falling over.
Preparation for removal Hold the machine by placing the
suitable stand under the engine.
1 Bolt (brake cable holder) 1 Only loosening.
2 Brake cable 1 Disconnect at the lever side.
3 Wheel axle nut 1
4 Front wheel axle 1
5 Front wheel 1
6 Collar set 1
7 Brake shoe plate assembly 1
8 Oil seal 1
9Bearing
2Refer to “REMOVAL POINTS”.
2
31
3

5 - 2
CHAS

Extent of removal Order Part name Q’ty Remarks
10 Brake shoe 2
11 Brake camshaft lever 1
12 Brake camshaft 1
3

FRONT WHEEL AND REAR WHEEL