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 (TT-R90) ........................4-39
CDI MAGNETO AND
STARTER CLUTCH (TT-R90E) ...............4-41
CRANKCASE AND CRANKSHAFT ........4-45
SHIFT FORK, SHIFT CAM AND
TRANSMISSION ......................................4-48
CHAPTER 5
CHASSIS
FRONT WHEEL AND REAR WHEEL .......5-1
FRONT FORK ..........................................5-10
HANDLEBAR ...........................................5-13
STEERING ...............................................5-18
SWINGARM .............................................5-20
CHAPTER 6
ELECTRICAL
ELECTRICAL COMPONENTS AND
WIRING DIAGRAM ....................................6-1
IGNITION SYSTEM ....................................6-3
ELECTRIC STARTING SYSTEM
(TT-R90E) ..................................................6-7
CHARGING SYSTEM (TT-R90E) ............6-15
CARBURETOR HEATING SYSTEM .......6-17
MAINTENANCE RECORD ......................6-21
GEN
INFO
1 - 7
SPECIAL TOOLS
YM-1312-A, 90890-01312 Fuel 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 type or grade:
Engine oil
(For USA and CDN)
At –10 °C (10 °F) or higher È
Yamalube 4 (10W-30) or SAE 10W-30 type
SE/SF/SG motor oil
At 5 °C (40 °F) or higher É
Yamalube 4 (20W-40) or SAE 20W-40 type
SE/SF/SG motor oil
(Except for USA and CDN)
API “SE/SF/SG” or higher grade
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 and ZA)
Tank capacity 4.2 L (0.92 Imp 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
0 10 30 50 70 90 110 130
-20 -10 01020
30 40 50
È
É
˚F
˚C
GENERAL SPECIFICATIONS
1
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 ~ 0.10 in) ----
Engine idle speed 1,400 ~ 1,600 r/min ----Item Standard Limit
CC
D
A
E
MAINTENANCE SPECIFICATIONS
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 10 1.0 7.2
Drive sprocket cover M6 × 1.0 2 7 0.7 5.1
Crankcase cover (right) M6 × 1.0 9 10 1.0 7.2
Timing plug M14 ×
1.5 1 7 0.7 5.1
Crankshaft end cover M32 ×
1.5 1 7 0.7 5.1
Kick crank M6 ×
1.0 1 10 1.0 7.2
Starter clutch and rotor (TT-R90E) M6 ×
1.0 3 14 1.4 10
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
Neutral switch (TT-R90E) M10 × 1.25 1 18 1.8 13
MAINTENANCE SPECIFICATIONS
3 - 1
INSP
ADJ
MAINTENANCE INTERVALS
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.
NOTE:
From 18 months or 210 hours, repeat the maintenance intervals starting from 6 months or
90 hours.
Items marked with an asterisk should be performed by a Yamaha dealer as they require special
tools, data and technical skills.
No. ITEMCHECKS AND
MAINTENANCE JOBSWHICH-
EVER
COMES
FIRSTINITIAL EVERY
month 1 6 12
hours 30 90 150
1 * Fuel lineCheck fuel hoses for cracks or damage.
Replace if necessary.√
√
2 Spark plugCheck condition.
Adjust gap and clean.√
√
3 * Valve clearanceCheck and adjust valve clearance when engine is
cold.√
4 * Air filter elementClean with solvent.
Replace if necessary.√
√
5 * Breather systemCheck ventilation hose for cracks or damage.
Replace if necessary.√
√
√
6 * CarburetorCheck engine idling speed and starter operation.
Adjust if necessary.√
√
√
7 Exhaust systemCheck for leakage.
Tighten if necessary.
Replace gasket if necessary.√
√
8 Engine oil Change (warm engine before draining).
√
√
√
9 ClutchCheck operation.
Adjust or replace cable.√
√
√
10 * Front brakeCheck operation.
Adjust brake lever free play and replace brake shoes
if necessary.√
√
√
11 * Rear brakeCheck operation.
Adjust brake pedal free play and replace brake shoes
if necessary.√
√
√
12 * WheelsCheck runout, spoke tightness and for damage.
Tighten spokes if necessary.√
√
√
13 * TiresCheck tread depth and for damage.
Replace if necessary.
Check air pressure.
Correct if necessary.√
√
14 * Wheel bearingsCheck bearings for smooth operation.
Replace if necessary.√
√
15 * SwingarmCheck swingarm pivoting point for play.
Correct if necessary.
Lubricate with lithium soap based grease.√
√
√
16 Drive chainCheck chain slack/alignment and condition.
Adjust and lubricate chain.Every ride
3
3 - 2
INSP
ADJ
MAINTENANCE INTERVALS
NOTE:
The air filter needs more frequent service if you are riding in unusually wet or dusty areas.
17 * Steering bearingsCheck bearing assemblies for looseness.
Lubricate with lithium soap based grease every or
120 hours or 12 months (whichever comes first).√
√
18Brake and clutch
lever pivot shaftsApply lithium soap based grease lightly.
√
√
√
19Brake pedal pivot
shaftApply lithium soap based grease lightly.
√
√
√
20 Sidestand pivotCheck operation.
Apply lithium soap based grease lightly.√
√
21 * Front forkCheck operation and for oil leakage.
Replace if necessary.√
√
22 *Shock absorber
assemblyCheck operation and for oil leakage.
Replace if necessary.√
√
23 * Control cablesApply Yamaha chain and cable lube or engine oil
10W-30 thoroughly.√
√
√
24 *Throttle grip hous-
ing and cableCheck operation and free play.
Adjust the throttle cable free play if necessary.
Lubricate the throttle grip housing and cable.√
√
√
25 * Chassis fastenersCheck all chassis fitting and fasteners.
Correct if necessary.√
√
√
26Battery (TT-R90E
only)Check terminal for looseness and corrosion.
√ No. ITEMCHECKS AND
MAINTENANCE JOBSWHICH-
EVER
COMES
FIRSTINITIAL EVERY
month 1 6 12
hours 30 90 150
3
3 - 6
INSP
ADJ
ENGINE OIL LEVEL INSPECTION
1. Start the engine, warm it up for several
minutes, and then turn off the engine 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:
Dipstick 1
4. Check:
Oil 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:
Do not add any chemical additives.
Engine oil also lubricates the clutch and
additives could cause clutch slippage.
Do not allow foreign material to enter the
crankcase.
Recommended oil:
At –10 °C (10 °F) or higher È:
Yamalube 4 (10W-30) or SAE
10W-30 type SE/SF/SG motor
oil
At 5 °C (40 °F) or higher É:
Yamalube 4 (20W-40) or SAE
20W-40 type SE/SF/SG motor
oil010 30 50 70
90110
130
-20
-10010
20 30 40
50
È
É
˚C ˚F
ENGINE OIL LEVEL INSPECTION