2002 YAMAHA TTR90 engine

2 - 17
SPECCABLE ROUTING DIAGRAM
1Cable guide
2Brake cable
3Throttle cable
4Fuel tank breather hose
5Engine stop switch lead
6Air vent hose
7Air intake duct
8Ignition coil
9Cable guide
0Wire harness
ADamperBCDI unit lead
CCDI unit
DRectifier/regulator lead
ERectifier/regulator
FCrankcase breather hose
GCarburetor breather hose
HSpark plug lead
IFuel hose
JStarter cable
KCDI magneto lead
LThermo switch
A
123
4
5
6
7
8
9
0A
C
E B
F G H I
6
6 J L
5
H
B8 K
7 ‚
ä
‚
ì
í
B - B C - C
D - DF - FE
õ
ë
D
D
B
D
A A B
B B
B
C
C C
CE
B D
B
D
F F F F

2 - 18
SPECCABLE ROUTING DIAGRAM
Pass the fuel tank breather hose through the
cable guide.
õPass the throttle cable and engine stop switch
lead through the cable guide.
‚Pass the air vent hose through the hose guide.
ëFasten the CDI unit lead and rectifier/regulator
lead with the plastic clamp.
äAlign the tape on the rectifier/regulator lead with
the plastic clamp.
ìAfter fastening the engine stop switch lead, cut
off any excess from the plastic locking tie end.íPass the CDI unit lead through the lead guide.
A
123
4
5
6
7
8
9
0A
C
E B
F G H I
6
6 J L
5
H
B8 K
7 ‚
ä
‚
ì
í
B - B C - C
D - DF - FE
õ
ë
D
D
B
D
A A B
B B
B
C
C C
CE
B D
B
D
F F F F

3 - 1
INSP
ADJMAINTENANCE INTERVALS/
PERIODIC MAINTENANCE AND LUBRICATION
EC300000
REGULAR INSPECTION AND ADJUSTMENTS
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

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 - 3
INSP
ADJENGINE/THROTTLE CABLE ADJUSTMENT/
AIR FILTER CLEANING
EC350000
ENGINE
THROTTLE CABLE ADJUSTMENT
1. Check:
lThrottle grip free play a
Out of specification ® Adjust.
Throttle grip free play a:
3 ~ 5 mm (0.12 ~ 0.20 in)
2. Adjust:
lThrottle grip free play
AIR FILTER CLEANING
NOTE:
Proper air filter maintenance is the biggest key
to preventing premature engine wear and
damage.
CAUTION:
Never run the engine without the air filter
element in place; this would allow dirt and
dust to enter the engine and cause rapid
wear and possible engine damage.Throttle grip free play adjustment steps:
NOTE:
Before adjusting the throttle cable free play,
the engine idle speed should be adjusted.
lLoosen the locknut 1 on throttle cable.
lTurn the adjuster 2 in or out until the
specified free play is obtained.
Turning in: Free play is increased.
Turning out: Free play is decreased.
lTighten the locknut.
WARNING
After adjusting, turn the handlebar to
right and left and make sure that the
engine idling does not run faster.

3 - 4
INSP
ADJ
AIR FILTER CLEANING
1. Install:
lAir scoop (right) 1
2. Install:
lAir filter case cover 1
3. Clean:
lAir filter element
Clean them with solvent.
NOTE:
After cleaning, remove the remaining solvent
by squeezing the element.
CAUTION:
lDo not twist the element when squeezing
the element.
lLeaving too much of solvent in the ele-
ment may result in poor starting.
4. Inspect:
lAir filter element
Damage ® Replace.
5. Apply:
lFoam-air-filter oil or engine mixing oil
To the element.
NOTE:
Squeeze out the excess oil. Element should
be wet but not dripping.
6. Install:
lAir filter element 1
NOTE:
Align the projection a on the air filter case with
the hole b in the air filter element.
7. Install:
lAir filter case cover
8. Install:
lAir scoop (right)

3 - 5
INSP
ADJ
ENGINE OIL LEVEL INSPECTION
1. Start the engine, warm it up for several
minutes and wait for five minutes.
2. Place the machine on a level place and
hold it up on upright position by placing
the suitable stand under the engine.
3. Remove:
lDipstick 1
4. Check:
lOil level
Oil level should be between maximum
a and minimum b marks.
Oil level is low ® Add oil to proper
level.
NOTE:
When inspecting the oil level, do not screw the
dipstick into the oil tank. Insert the gauge
lightly.
(For USA and CDN)
CAUTION:
lDo not add any chemical additives.
Engine oil also lubricates the clutch and
additives could cause clutch slippage.
lDo not allow foreign material to enter the
crankcase.
Recommended oil:
At –10 ˚C (10 ˚F) or higher :
Yamalube 4 (10W-30) or SAE
10W-30 type SE/SF motor oil
At 5 ˚C (40 ˚F) or higher õ:
Yamalube 4 (20W-40) or SAE
20W-40 type SE/SF motor oil010 30 50 70
90110
130
-20
-10010
20 30 40
50

õ
˚C˚F
ENGINE OIL LEVEL INSPECTION

3 - 6
INSP
ADJ
ENGINE OIL REPLACEMENT
(Except for USA and CDN)
CAUTION:
lDo not add any chemical additives or use
oils with a grade of CD a or higher.
lDo not use oils labeled “ENERGY CON-
SERVING II” b or higher. Engine oil also
lubricates the clutch and additives could
cause clutch slippage.
lDo not allow foreign materials to enter the
crankcase.
5. Install:
lDipstick
6. Start the engine and let it warm up for
several minutes.
7. Turn off the engine and inspect the oil
level once again.
NOTE:
Wait a few minutes until the oil settles before
inspecting the oil level.
ENGINE OIL REPLACEMENT
1. Start the engine and warm it up for sev-
eral minutes and wait for five minutes.
2. Place the machine on a level place and
hold it on upright position by placing the
suitable stand under the engine.
3. Place a suitable container under the
engine.
4. Remove:
lDipstick 1
lDrain bolt (with gasket) 2
Drain the crankcase of its oil.
Recommended oil:
Refer to the following chart for
selection of oils which are suited
to the atmospheric temperatures.
Recommended engine oil classi-
fication:
API STANDARD:
API “SE/SF” or higher grade
(Designed primarily for motor-
cycles)
a
b