engine YAMAHA TTR90 2003 Owner's Manual

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 4.1 L (0.90 Imp gal, 1.08 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 kgf/cm
2

, 14.5 psi)
GENERAL SPECIFICATIONS
2

SPEC

2 - 4
MAINTENANCE SPECIFICATIONS
ENGINE
Item Standard Limit
Cylinder head:
Warp limit ---- 0.03 mm
(0.0012 in)
Cylinder:
Bore size 47.000 ~ 47.005 mm
(1.8504 ~ 1.8506 in)47.05 mm
(1.8524 in)
Out of round limit ---- 0.05 mm
(0.0020 in)
Camshaft:
Drive method Chain drive (left) ----
Cam dimensions
Intake“A”25.428 ~ 25.528 mm
(1.0011 ~ 1.0050 in)25.400 mm
(1.0000 in)
“B”21.034 ~ 21.134 mm
(0.8281 ~ 0.8320 in)21.000 mm
(0.8268 in)
Exhaust“A”25.286 ~ 25.386 mm
(0.9955 ~ 0.9994 in)25.260 mm
(0.9945 in)
“B”21.047 ~ 21.147 mm
(0.8286 ~ 0.8326 in)21.017 mm
(0.8274 in)
Camshaft runout limit ---- 0.03 mm
(0.0012 in)
MAINTENANCE SPECIFICATIONS

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 - 13
NOTE:
1. First, tighten the ring nut approximately 38 Nm (3.8 m • kg, 27 ft • lb) by using the ring nut
wrench and turn the steering right and left a few times; then loosen the ring nut one turn.
2. Retighten the ring nut 1 Nm (0.1 m • kg, 0.7 ft • lb).
-marked portion shall be checked for torque tightening after break-in or before each ride.Part to be tightened Thread size Q’tyTightening torque
Nm m•kg ft•lb
Engine mounting:
Engine and frame (front-upper) M8 × 1.25 1 30 3.0 22
Engine and frame (rear-upper) M8 × 1.25 1 26 2.6 19
Engine and frame (rear-lower) M10 × 1.25 1 48 4.8 35
Starter cable and frame M11 × 1.25 1 1 0.1 0.7
Pivot shaft and nut M10 × 1.25 1 30 3.0 22
Handle crown and steering shaft M10 × 1.25 1 40 4.0 29
Front fork cap bolt M20 × 1.0 2 40 4.0 29
Under bracket and front fork M10 × 1.25 2 33 3.3 24
Damper rod bolt M8 × 1.25 2 20 2.0 14
Handle crown and handlebar holder (lower) M10 × 1.25 2 40 4.0 29
Handlebar holder (upper) M8 × 1.25 4 23 2.3 17
Front brake cable holder and front fork M6 × 1.0 2 7 0.7 5.1
Steering ring nut M25 1 Refer to NOTE.
Fuel tank and fuel cock M6 × 1.0 2 7 0.7 5.1
Fuel tank and frame M6 × 1.0 2 7 0.7 5.1
Grab bar and frame M6 × 1.0 4 13 1.3 9.4
Front brake camshaft lever and camshaft M6 × 1.0 1 7 0.7 5.1
Rear brake camshaft lever and camshaft M6 × 1.0 1 7 0.7 5.1
Front wheel axle nut M10 × 1.25 1 35 3.5 25
Rear brake shoe plate tension bar M8 × 1.25 2 26 2.6 19
Wheel drive hub and driven sprocket M8 × 1.25 4 25 2.5 18
Rear wheel axle nut M12 × 1.25 1 60 6.0 43
Wheel nipple (spoke)—64 2 0.2 1.4
Drive chain guard M5 × 0.8 2 4 0.4 2.9
Drive chain support M5 × 0.8 3 4 0.4 2.9
Chain puller locknut M6 × 1.0 2 7 0.7 5.1
Footrest and frame M8 × 1.25 2 30 3.0 22
Battery box M6 × 1.0 3 5 0.5 3.6
MAINTENANCE SPECIFICATIONS

2 - 16
SPEC

GENERAL TORQUE SPECIFICATIONS/
DEFINITION OF UNITS
EC220001
GENERAL TORQUE SPECIFICATIONS
This chart specifies torque for standard fasten-
ers with standard I.S.O. pitch threads. Torque
specifications for special components or
assemblies are included in the applicable sec-
tions of this book. To avoid warpage, tighten
multi-fastener assemblies in a crisscross fash-
ion, in progressive stages, until full torque is
reached. Unless otherwise specified, torque
specifications call for clean, dry threads. Com-
ponents should be at room temperature.
A
(Nut)B
(Bolt)TORQUE
SPECIFICATION
Nm m•kg ft•lb
10 mm
12 mm
14 mm
17 mm
19 mm
22 mm6 mm
8 mm
10 mm
12 mm
14 mm
16 mm6
15
30
55
85
1300.6
1.5
3.0
5.5
8.5
134.3
11
22
40
61
94
A: Distance between flats
B: Outside thread diameter
EC230000
DEFINITION OF UNITS
Unit Read Definition Measure
mm
cmmillimeter
centimeter10
-3

meter
10
-2

meterLength
Length
kg kilogram 10
3

gram Weight
N Newton 1 kg
×
m/sec
2

Force
Nm
m • kgNewton meter
Meter kilogramN
×
m
m
×
kgTorque
Torque
Pa Pascal N/m
2

Pressure
N/mm Newton per millimeter N/mm Spring rate
L
cm
3

Liter
Cubic centimeter—
—Volume or capacity
Volume or capacity
r/min Revolution per minute—Engine speed

2 - 17
SPEC

CABLE ROUTING DIAGRAM
CABLE ROUTING DIAGRAM
1
Crankcase breather hose
2
CDI magneto lead
3
Wire harness
4
Thermo switch
5
Thermo switch lead
6
CDI unit lead
7
Spark plug lead
8
Starter cable
9
Starter relay lead
0
Starter motor lead
A
Starter motor
B
Throttle cable
C
Brake cable
D
Engine stop switch lead
E
Main switch lead
F
Start switch lead
Å
Pass the spark plug lead
through the lead guide.
ı
Make sure that the starter cable
does not contact the engine
bracket.
Ç
Fasten the engine stop lead with
the plastic bands.
Î
Pass the brake cable through
the cable guide.
‰
Fasten the start switch lead with
the plastic bands.
30 ~ 40 mm
(1.18 ~ 1.57 in)A
B
40 ~ 50 mm
(1.57 ~ 1.97 in)
1
B
C
D
E ‰
F
ÎÎÇ A875 4
6 3
2
1
Å
ı
A
B
0
9

2 - 18
SPEC

CABLE ROUTING DIAGRAM
1
Clamp
2
Engine stop switch lead
3
Main switch lead
4
Start switch lead
5
Brake cable
6
Throttle cable
7
Fuel tank breather hose
8
Ignition coil
9
Wire harness
0
Starter relay
A
Starter motor lead
B
Crankcase breather hose
C
Starter motor lead
D
Neutral switch lead
E
CDI magneto lead
F
CDI unit
G
Fuel 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
Ë
25 mm (1.0 in)
∏
‰

2 - 19
SPECCABLE ROUTING DIAGRAM
ÅPass the start switch lead, main
switch lead, engine stop switch
lead and throttle cable through
the cable guide.
ıPass the fuel tank breather hose
through the hose guide.
ÇPass the carburetor breather
hose through the hose guide.
ÎFasten the carburetor heater lead,
main switch lead, engine stop
switch lead and start switch lead.‰After fastening the CDI mag-
neto lead, cut off any excess
from the plastic locking tie end.
ÏFasten the battery leads to the
bracket with the plastic locking
tie. For fastening, pass the plas-
tic locking tie through the hole in
the bracket.
ÌAfter fastening the starter motor
lead, cut off any excess from the
plastic locking tie end.ÓAfter fastening the CDI mag-
neto lead, cut off any excess
from the plastic locking tie end.
ÈPosition the start switch coupler
and engine stop switch coupler
between the carburetor breather
hose and thermo switch.
ÔMake sure that the CDI unit lead
does not contact the thermo
switch bracket.
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
Ë
25 mm (1.0 in)
∏
‰

2 - 20
SPEC
Fasten the starter cable, thermo
switch lead, CDI unit lead, main
switch lead, start switch lead
and engine stop switch lead.
ÒFasten the wire harness, CDI
unit leads, thermo switch lead
and CDI magneto lead.
˜Pass the carburetor heater lead
between the carburetor breather
hose and air intake duct.ˆPosition the main switch cou-
pler between the carburetor
breather hose and air intake
duct.
ØFasten the start switch lead,
main switch lead and engine
stop switch lead at the tape with
the plastic locking tie.
∏Fasten the battery leads.ŒFasten the wire harness and
starting circuit cut-off relay lead
at the tape for the wire harness
with the plastic locking tie.
ÂFasten the rectifier/regulator
lead and starter relay leads. For
fastening, pass the plastic lock-
ing tie through the hole in the
battery box.
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
Ë
25 mm (1.0 in)
∏
‰
CABLE ROUTING DIAGRAM

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