2002 YAMAHA TTR90 clutch

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

1 - 7
GEN
INFO
SPECIAL TOOLS
YM-1312-A, 90890-01312Fuel level gauge
This gauge is used to measure the fuel level in the
float chamber.YM-1312-A 90890-01312
YM-1326, 90890-01326 T-handle
This tool is used for holding the damper rod holder
when removing or installing the damper rod holder.YM-1326 90890-01326
90890-01186 Fork seal driver attachment
This tool is used to installing the oil seal.90890-01186
YM-8035, 90890-01311 Valve adjusting tool
This tool is necessary for adjusting valve clearance.YM-8035 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-1880-A, 90890-01701 Sheave holder
This tool is used for when loosening or tightening the
flywheel magneto securing nut.YS-1880-A 90890-01701
Part number Tool name/How to use Illustration

SPEC
2 - 2
Oil capacity:
Engine oil
Periodic oil change 0.8 L (0.70 Imp qt, 0.85 US qt)
Total amount 1.0 L (0.88 Imp qt, 1.06 US qt)
Air filter: Wet type element
Fuel:
Type Unleaded gasoline only (USA, AUS and NZ)
Regular unleaded gasoline only (CDN, Europe)
Regular gasoline (ZA)
Tank capacity 4.2 L (0.92 lmp gal, 1.11 US gal)
Reserve amount 0.5 L (0.11 Imp gal, 0.13 US gal)
Carburetor:
Type VM16SH
Manufacturer MIKUNI
Spark plug:
Type CR6HSA/U20FSR-U
Manufacturer NGK/DENSO
Gap 0.6 ~ 0.7 mm (0.02 ~ 0.03 in)
Clutch type: Wet, multiple-disc and centrifugal automatic
Transmission:
Primary reduction system Spur gear
Primary reduction ratio 67/18 (3.722)
Secondary reduction system Chain drive
Secondary reduction ratio 35/14 (2.500)
Transmission type Constant mesh, 3-speed
Operation Left foot operation
Gear ratio: 1st 37/13 (2.846)
2nd 33/19 (1.736)
3rd 28/23 (1.217)
Chassis:
Frame type Double cradle
Caster angle 24.83˚
Trail 56.0 mm (2.2 in)
Tire:
Type With tube
Size (front) 2.50-14 4PR
Size (rear) 3.00-12 4PR
Manufacturer (front and rear) CHENG SHIN
Type (front and rear) KNOBBY
Tire pressure (front and rear) 100 kPa (1.00 kg/cm
2, 14.5 psi)
GENERAL SPECIFICATIONS
2

SPEC
2 - 8
Crankshaft:
Crank width “A” 42.95 ~ 43.00 mm
(1.691 ~ 1.693 in)----
Runout limit C ---- 0.03 mm
(0.0012 in)
Big end side clearance “D” 0.10 ~ 0.40 mm
(0.0039 ~ 0.0157 in)0.50 mm
(0.02 in)
Big end radial clearance “E” 0.010 ~ 0.025 mm
(0.0004 ~ 0.0010 in)0.05 mm
(0.002 in)
Clutch:
Friction plate thickness 2.7 ~ 2.9 mm
(0.106 ~ 0.114 in)2.6 mm
(0.102 in)
Quantity 5 ----
Clutch plate thickness 1.1 ~ 1.3 mm (0.043 ~ 0.051 in) ----
Quantity 4 ----
Warp limit ---- 0.2 mm
(0.008 in)
Clutch spring free length 26.2 mm (1.03 in) 24.2 mm
(0.95 in)
Quantity 4 ----
Clutch release method Inner push, cam push ----
Push rod bending limit ---- 0.5 mm
(0.02 in)
Automatic centrifugal clutch: ----
Clutch-in revolution 2,160 ~ 2,560 r/min ----
Clutch-stall revolution 3,300 ~ 3,800 r/min
Shifter:
Shifter type Cam drum and guide bar ----
Kick starter:
Type Ratchet type ----
Kick clip friction force 5.8 ~ 14.7 N
(0.59 ~ 1.50 kg, 1.3 ~ 3.3 lb)
Carburetor:
I. D. mark 5HN1 01 ----
Main jet (M.J) #90 ----
Main air jet (M.A.J) ø 1.1 ----
Jet needle (J.N) 4E9-2 ----
Cutaway (C.A) 2.5 ----
Pilot outlet (P.O) ø 1.0 ´ 2.0 ----
Pilot jet (P.J) #12.5 ----
Valve seat size (V.S) ø 1.5 ----
Starter jet 1 (G.S.1) #37.5 ----
Pilot air screw 1-3/4 turns out
Float height (F.H) 15.5 ~ 16.5 mm (0.61 ~ 0.65 in) ----
Fuel level (F.L) 2 ~ 3 mm (0.08 ~ 0.1 in) ----
Engine idle speed 1,400 ~ 1,600 r/min ----Item Standard Limit
MAINTENANCE SPECIFICATIONS
CC
D
A
E

SPEC
2 - 10
Part to be tightened Thread size Q’tyTightening torque
Nm m•kg ft•lb
Cylinder head nut M8 ´ 1.25 4 22 2.2 16
Cylinder head bolt M6 ´ 1.0 2 10 1.0 7.2
Spark plug M10 ´ 1.0 1 13 1.3 9.4
Camshaft sprocket cover bolt M6 ´ 1.0 2 7 0.7 5.1
Tappet cover M45 ´ 1.5 2 18 1.8 13
Exhaust pipe stud bolt M6 ´ 1.0 2 7 0.7 5.1
Rotor nut M12 ´ 1.25 1 48 4.8 35
Timing chain guide (rear) M6 ´ 1.0 2 10 1.0 7.2
Valve clearance adjust screw locknut M5 ´ 0.5 2 7 0.7 5.1
Camshaft sprocket M8 ´ 1.25 1 20 2.0 14
Camshaft bearing retainer M6 ´ 1.0 1 10 1.0 7.2
Timing chain tensioner cap bolt M8 ´ 1.25 1 8 0.8 5.8
Timing chain tensioner M6 ´ 1.0 2 10 1.0 7.2
Oil pump M6 ´ 1.0 2 7 0.7 5.1
Drain bolt M12 ´ 1.5 1 20 2.0 14
Carburetor joint (cylinder head side) M6 ´ 1.0 2 7 0.7 5.1
Carburetor joint (carburetor side) M6 ´ 1.0 2 7 0.7 5.1
Air filter case M6 ´ 1.0 2 7 0.7 5.1
Exhaust pipe M6 ´ 1.0 2 7 0.7 5.1
Exhaust pipe protector M6 ´ 1.0 7 7 0.7 5.1
Silencer M8 ´ 1.25 1 24 2.4 17
Silencer protector M5 ´ 0.8 2 4 0.4 2.9
Crankcase M6 ´ 1.0 9 10 1.0 7.2
Crankcase cover (left) M6 ´ 1.0 8 7 0.7 5.1
Drive sprocket cover M6 ´ 1.0 2 7 0.7 5.1
Crankcase cover (right) M6 ´ 1.0 9 7 0.7 5.1
Timing plug M14 ´ 1.5 1 7 0.7 5.1
Crankshaft end cover M32 ´ 1.5 1 7 0.7 5.1
Cylinder head stud bolt M8 ´ 1.25 4 13 1.3 9.4
Kick crank M6 ´ 1.0 1 10 1.0 7.2
Primary drive gear M12 ´ 1.0 1 50 5.0 36
Pressure plate M5 ´ 0.8 4 6 0.6 4.3
Clutch boss M14 ´ 1.0 1 70 7.0 50
Main axle bearing retainer M6 ´ 1.0 1 10 1.0 7.2
Shift pedal M6 ´ 1.0 1 8 0.8 5.8
Clutch adjust screw locknut M6 ´ 1.0 1 8 0.8 5.8
Pickup coil M6 ´ 1.0 2 10 1.0 7.2
Stator assembly M6 ´ 1.0 3 10 1.0 7.2
MAINTENANCE SPECIFICATIONS

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 - 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