2002 YAMAHA TTR90 wheel

3 - 2
INSP
ADJ
PRE-OPERATION INSPECTION AND MAINTENANCE
*: Since these items requires special tools data and technical skills, they should be serviced.
*1: For USA
SERVICE NOTES:
No. 1. DRIVE CHAIN: In addition to tension and alignment, chain must be lubricated every
0.5 ~ 1.0 hour. If unit is subjected to extremely hard usage and wet weather riding, chain
must be checked constantly. See “Lubrication Intervals” for additional details.
No. 2. AIR FILTER: Remove and clean filter every 20 ~ 40 hours.
PRE-OPERATION INSPECTION AND MAINTENANCE
Before riding for break-in operation, practice or a race, make sure the machine is in good operating
condition.
Before using this machine, check the following points.
GENERAL INSPECTION AND MAINTENANCE
* Chassis fastenersMake sure that all nuts, bolts and screws are
properly tightened.
Tighten if necessary.
SidestandCheck operation.
Lubricate and repair if necessary.
* Spark arrester*1Clean.
* Front forkCheck operation and for oil leakage.
Correct accordingly.
*Rear shock
absorber assemblyCheck operation and shock absorber for oil
leakage.
Replace shock absorber assembly if necessary.
Item Routine Page
Brake Check operation/adjustment. P3-11
Engine oil Change oil as required. P3-5 ~ 7
Drive chain Check alignment/adjustment/lubrication. P3-12
Spark plug Check color/condition. P3-19
Throttle Check for proper throttle cable operation. P3-3
Air filter Foam type – must be clean and damp oil always P3-3 ~ 4
Wheels and tires Check pressure/runout/spoke tightness/bead stopper/axle nuts. P3-15 ~ 17
Fittings/fasteners Check all – tighten as necessary. P2-13Dealer
NoteItem Checks and maintenance jobsInitial Every
10 hours
(1 month)60 hours
(6 months)120 hours
(12 months)
3

3 - 12
INSP
ADJ
DRIVE CHAIN SLACK ADJUSTMENT
DRIVE CHAIN SLACK ADJUSTMENT
1. Elevate the rear wheel by placing the
suitable stand under the engine.
2. Check:
lDrive 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. Adjust:
lDrive chain slack
Drive chain slack adjustment steps:
lLoosen the wheel axle nut 1.
lAdjust chain slack by turning the adjusters
2.
To tighten ®Turn adjuster 2 clockwise.
To loosen ®Turn adjuster 2 counter-
clockwise and push wheel
forward.
lTurn 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.
12 a

3 - 13
INSP
ADJFRONT FORK INSPECTION/REAR SHOCK ABSORBER INSPECTION/
REAR SHOCK ABSORBER SPRING PRELOAD ADJUSTMENT
lTighten the wheel axle nut while pushing
down the drive chain.
T R..
Axle nut:
60 Nm (6.0 m • kg, 43 ft • lb)
EC36C000
FRONT FORK INSPECTION
1. Inspect:
lFront 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:
lSwingarm 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:
lRear shock absorber
Refer to “SWINGARM” section in the
CHAPTER 5.
3. Remove:
lSpring 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:
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 Nm (0.2 m · kg, 1.4 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.
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.

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 - 40
ENGCDI MAGNETO
REMOVAL POINTS
Rotor
1. Remove:
lRotor nut 1
lWasher 2
NOTE:
lLoosen the rotor nut while holding the rotor
with sheave holder 3.
lDo not allow the sheave holder to touch the
projection on the rotor.
Sheave holder:
YS-1880-A/90890-01701
2. Remove:
lRotor 1
lWoodruff key
NOTE:
lUse the flywheel puller 2.
lCenter 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 - 45
ENGSHIFT FORK, SHIFT CAM AND TRANSMISSION
Extent of removal Order Part name Q’ty Remarks
10 3th 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 removal2 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 nodanger 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