wheel YAMAHA TTR90 2006 User Guide

3 - 14
INSP
ADJ
DRIVE CHAIN SLACK ADJUSTMENT
5. Install:
Drive chain 1
Joint 2
Master link clip 3
CAUTION:
Be sure to install the master link clip to the
direction as shown.
aTurning direction
New
6. Lubricate:
Drive chain
Drive chain lubricant:
SAE 10W-30 motor oil or
suitable chain lubricants
DRIVE CHAIN SLACK ADJUSTMENT
1. Elevate the rear wheel by placing the suit-
able stand under the engine.
2. Check:
Drive chain slack
a
In the center between the drive axle and
rear wheel axle.
Out of specification → Adjust.
NOTE:
Before checking and/or adjusting, rotate the
rear wheel through several revolutions and
check the slack several times to find the tight-
est point. Check and/or adjust chain slack with
rear wheel in this “tight chain” position.
Drive chain slack:
40 ~ 53 mm (1.6 ~ 2.1 in)

3 - 15
INSP
ADJ
FRONT FORK INSPECTION
3. Adjust:
Drive chain slack
Drive chain slack adjustment steps:
Loosen the wheel axle nut 1 and locknuts
2.
Adjust chain slack by turning the adjusters
3.
To tighten
→ Turn adjuster
3 clockwise.
To loosen
→ Turn adjuster
3 counter-
clockwise and push wheel forward.
Turn each adjuster exactly the same
amount to maintain correct axle alignment.
(There are marks a on each side of chain
puller alignment.)
NOTE:
Turn the adjuster so that the chain is in line
with the sprocket, as viewed from the rear.
CAUTION:
Too small chain slack will overload the
engine and other vital parts; keep the
slack within the specified limits.
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)
13 a2
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.

3 - 16
INSP
ADJREAR SHOCK ABSORBER INSPECTION/
REAR SHOCK ABSORBER SPRING PRELOAD ADJUSTMENT
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 suit-
able 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.
4. To stiffen the spring preload, install the cir-
clip 1 into the groove a. To soften the
spring preload, install the circlip into the
groove b.
NOTE:
Do not spread the circlip too much.
Standard installation position:
Groove b
5. Install:
Spring guide 1
NOTE:
While compressing the spring, install the
spring guide.

3 - 18
INSP
ADJWHEEL INSPECTION/
STEERING HEAD INSPECTION AND ADJUSTMENT
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 gently
rock the fork assembly back and forth.
Free play → Adjust steering head.
3. Check:
Steering smooth action
Turn the handlebar lock to lock.
Unsmooth action → Adjust steering ring
nut.
4. Adjust:
TT-R90
Steering ring nut
Steering ring nut adjustment steps:
Remove the front fender 1.
Remove the handlebar and handle crown.
Loosen the ring nut 2 using the ring nut
wrench 3.

4 - 33
ENGKICK AXLE
KICK AXLE
Extent of removal:
1 Kick axle removal
2 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
8Clip 1
9 Circlip 1
10 Washer/wave washer 1/1
11 Kick gear 1
12 Kick axle 1
2
1

4 - 40
ENG
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
CDI MAGNETO (TT-R90)

4 - 41
ENGCDI MAGNETO AND STARTER CLUTCH (TT-R90E)
CDI MAGNETO AND STARTER CLUTCH (TT-R90E)
Extent of removal:
1 Pickup coil/stator removal
2 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
6Shaft 1
7 Idler gear 1
8 Starter clutch/wheel gear 1/1
2
1
3

4 - 42
ENGCDI MAGNETO AND STARTER CLUTCH (TT-R90E)
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 - 43
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 È, 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 É, it should turn freely.
If not, the starter clutch is faulty. Replace
it.
É
È
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 (TT-R90E)

4 - 44
ENGCDI MAGNETO AND STARTER CLUTCH (TT-R90E)
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