Page 73 of 364
SPEC
2 - 16 Starter relay:
Model/manufacturer MS5F-751/JIDECO ----
Amperage rating 180 A ----
Coil winding resistance 4.2 ~ 4.6 Ω at 20 ˚C (68 ˚F) ----
Starting circuit cut-off relay:
Model/manufacturer ACM33221/MATSUSHITA ----
Coil winding resistance 75.69 ~ 92.51 Ω at 20 ˚C (68 ˚F) ----
Fuse (amperage × quantity):
Main fuse 10 A × 1 ----
Reserve fuse 10 A × 1 ---- Item Standard Limit
MAINTENANCE SPECIFICATIONS
Page 78 of 364
2 - 4
CARACTERISTIQUES D’ENTRETIENSPEC
CARACTERISTIQUES D’ENTRETIEN
MOTEUR
Désignation Standard Limite
Culasse:
Limite de déformation ---- 0,03 mm
(0,0012 in)
Cylindre:
Alésage 47,000 à 47,005 mm
(1,8504 à 1,8506 in)47,05 mm
(1,8524 in)
Limite d’ovalisation ---- 0,05 mm
(0,0020 in)
Arbre à cames:
Méthode d’entraînement Transmission par chaîne
(côté gauche)----
Dimensions de came
Admission“A” 25,428 à 25,528 mm
(1,0011 à 1,0050 in)25,400 mm
(1,0000 in)
“B” 21,034 à 21,134 mm
(0,8281 à 0,8320 in)21,000 mm
(0,8268 in)
Echappement“A” 25,286 à 25,386 mm
(0,9955 à 0,9994 in)25,260 mm
(0,9945 in)
“B” 21,047 à 21,147 mm
(0,8286 à 0,8326 in)21,017 mm
(0,8274 in)
Limite de voile d’arbre à cames ---- 0,03 mm
(0,0012 in)
Page 85 of 364

2 - 11
CARACTERISTIQUES D’ENTRETIENSPEC
PARTIE-CYCLE
Désignation Standard Limite
Système de direction:
Type de roulement de direction Roulement à contact oblique ----
Suspension avant:
Débattement de fourche avant 110 mm (4,33 in) ----
Longueur libre de ressort de fourche 425,1 mm (16,74 in) 417 mm (16,4 in)
Longueur de ressort de fourche installé415,1 mm (16,34 in) ----
Constante standard de ressort K = 3,4 N/mm
(0,35 kg/mm, 19,41 lb/in)----
Ressort/entretoise en option Non ----
Capacité d’huile 64 cm
3
(2,26 Imp oz, 2,16 US oz) ----
Niveau d’huile 185 mm (7,28 in) ----
Grade d’huile Huile de fourche 15W ou huile équiva-
lente----
Suspension arrière:
Débattement d’amortisseur 48 mm (1,89 in) ----
Longueur libre de ressort 169 mm (6,65 in) ----
Longueur monté165 mm (6,5 in) ----
Constante standard de ressort K = 45,6 N/mm
(4,65 kg/mm, 260 lb/in)----
Ressort optionnel Non ----
Pression du gaz 2.000 kPa
(20 kg/cm
2, 290 psi)----
Bras oscillant:
Limite de jeu du bras oscillant
A l’extrémité---- 1,0 mm (0,04 in)
Latéral ---- 0,3 mm (0,01 in)
Roue:
Type de roue avant Roue à rayons ----
Type de roue arrière Roue à rayons ----
Taille/matériau de jante avant 14 × 1,40/acier ----
Taille/matériau de jante arrière 12 × 1,60/acier ----
Limite de voile de jante:
Radial ---- 2,0 mm (0,08 in)
Latéral ---- 2,0 mm (0,08 in)
Chaîne de transmission:
Type/fabricant DID420(I)/DAIDO ----
Nombre de maillons 86 maillons ----
Flèche de la chaîne 40 à 53 mm (1,6 à 2,1 in) ----
Longueur de chaîne (15 maillons) ---- 194,3 mm (7,65 in)
Page 110 of 364
2 - 18
SPEC
CABLE ROUTING DIAGRAM
TT-R90
1Crankcase breather hose
2Wire harness
3CDI magneto lead
4Starter cable
5Carburetor heating lead
6Engine stop switch lead
7Thermo switch
8Thermo switch lead
9Spark plug lead0Throttle cable
ACable holder
BFuel tank breather hose
CBrake cable
ÅAfter fastening the starter cable, CDI magneto lead, wire harness and
thermo switch lead, cut off any excess from the plastic locking tie end.
ıPass the ignition coil lead through the lead guide.
ÇFasten the engine stop switch lead with the plastic bands.
ÎPass the brake cable through the cable guides.
12345
9
0
B A
6
C 1Å
ı
Ç
Î
Î
A
A
67
8
20 ~ 30 mm
(0.79 ~ 1.18 in)
CABLE ROUTING DIAGRAM
Page 112 of 364
2 - 19
SPEC
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 ÅÇ
‰
Ç
Ï
Ì
B - B C - C
D - DF - FE
ı
Î
D
D
B
D
A A B
B B
B
C
C C
CE
B D
B
D
F F F F
CABLE ROUTING DIAGRAM
Page 118 of 364
2 - 22
SPECCABLE ROUTING DIAGRAM
1Clamp
2Engine stop switch lead
3Main switch lead
4Start switch lead
5Brake cable
6Throttle cable
7Fuel tank breather hose
8Ignition coil
9Wire harness
0Starter relay
AStarter motor leadBCrankcase breather hose
CStarter motor lead
DNeutral switch lead
ECDI magneto lead
FCDI unit
GFuel overflow hose
HSpark plug lead
IFuel hose
JCarburetor heater lead
KCarburetor breather hose
LCarburetor heater couplerMCDI magneto coupler
NCDI unit coupler
OCDI unit connector
PCDI unit lead
QThermo switch lead
RThermo switch
SStarting circuit cut-off relay
TStarting circuit cut-off relay lead
URectifier/regulator lead
VRectifier/regulator
WStarter relay lead
A AA
C C
D
B
B B
BF FF
EE
D
A - AB - BE - E
C
F - FG - GD
KK
QRÔ
8
E
H
˜ 2 3 4
6
5
4
3
2
1
J
I
H
G
F
E
D
CBA 0 Ï 9 8 Î K 7
S
W U
V
A
0
Í T
99
QP
PT
9
Ò
ˆ Ø
Ç ı
Å
Ó
Œ
Â
E
GGA
P
O
NML 9
È
9
Ì
Ê
◊
25 mm (1.0 in)
∏
‰
35 ~ 45 mm
(1.38 ~ 1.77 in)
30 ~ 40 mm
(1.18 ~ 1.57 in)
Ë
Page 126 of 364

3 - 1
INSP
ADJ
MAINTENANCE 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
Page 127 of 364

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
*
1
Clean.
* 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.
Battery
(TT-R90E only)Check terminal for corrosion.
Clean 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 ~ 13
Spark plug Check color/condition. P3-20
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. P3-14 ~ 15
Fittings/fasteners Check all – tighten as necessary. P2-13 Dealer
NoteItem Checks and maintenance jobsInitial Every
10 hours
(1 month)60 hours
(6 months)120 hours
(12 months)
3