2003 YAMAHA TTR90 engine

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GEN
INFO
CONTROL FUNCTIONS
FUEL COCK
The fuel cock supplies fuel from the tank to
carburetor while filtering the fuel. The fuel cock
has the three positions:
OFF: With the lever in this position, fuel will
not flow. Always return the lever to this
position when the engine is not running.
ON: With the lever in this position, fuel flows
to the carburetor. Normal riding is done
with the lever in this position.
RES: This indicates reserve. If you run out of
fuel while riding, move the lever to this
position. FILL THE TANK AT THE
FIRST OPPORTUNITY. BE SURE TO
SET THE LEVER TO “ON” AFTER
REFUELING.
STARTER LEVER (CHOKE)
When cold, the engine requires a richer air/fuel
mixture for starting. A separate starter circuit,
which is controlled by the starter lever 1, sup-
plies this mixture.
Pull the lever out to open the circuit (for start-
ing) and push the lever in to close the circuit.
FUEL TANK CAP
Remove the fuel tank cap 1 by turning
counter-clockwise.
WARNING
Do not overfill the fuel tank. Avoid spilling
fuel on the hot engine.
1
TOOL KIT
Spark plug wrench
Spark plug wrench 1 is used to remove and
install the spark plug.
Screw driver
This tool is used for preventive maintenance
and minor repairs.
1

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GEN
INFO
FUEL
Use regular gasoline. Always use fresh, name
brand gasoline.
WARNING
Do not overfill the fuel tank. Avoid spilling
fuel on the hot engine. Do not fill the fuel
tank above the bottom of the filler tube 1
as shown in the illustration or it may over-
flow when the fuel heats up later and
expands.
aFuel level
CAUTION:
Use only unleaded gasoline. The use of
leaded gasoline will cause severe damage
to the engine internal parts such as valves,
piston rings, and exhaust system, etc.
Recommended fuel:
For USA, AUS and NZ:
Unleaded gasoline only
For CDN and EUROPE:
Regular unleaded gasoline
only
For ZA:
Regular gasoline
Fuel tank capacity:
Total:
4.1 L (0.90 Imp gal, 1.08 US gal)
Reserve:
0.5 L (0.11 lmp gal, 0.13 US gal)
FUEL

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GEN
INFO
STARTING AND OPERATION
STARTING AND OPERATION
CAUTION:
Prior to operating the machine, perform
steps listed in pre-operation check list.
WARNING
Never start your engine or let it run for any
length of time in a closed area. The exhaust
fumes are poisonous and can cause loss of
consciousness and death within a short
time. Always operate your machine in an
area with adequate ventilation.
STARTING A COLD ENGINE
WARNING
Before starting the engine, be sure to shift
the transmission into neutral.
NOTE:
This model is equipped with an ignition cir-
cuit cut-off system. In case of electric start-
ing, the engine can be started only when the
transmission is in neutral.
If the engine fails to start by pushing the start
switch, release the switch, wait a few sec-
onds, and then try again. Each starting
attempt should be as short as possible to
preserve the battery. Do not crank the
engine more than 10 seconds on any one
attempt. If the engine does not start with the
starter motor, try using the kickstarter.
1. Turn the fuel cock to “ON”.
2. Turn the main switch to “ON”.
3. Shift the transmission into neutral.
4. Operate the starter (choke) and com-
pletely close the throttle grip.
5. Start the engine by pushing the start
switch or by kicking the kickstarter.
6. After the engine starts, warm up for one
or two minutes. Make sure the stater
(choke) is returned to the original position
before riding.STARTING A WARM ENGINE
To start a warm engine, refer to the “Starting a
cold engine” section. The starter (choke)
should not be used. The throttle should be
opened slightly.
CAUTION:
See “Engine break-in Section” prior to
operating engine for the first time.
WARMING UP
To get maximum engine life, always “warm-up”
the engine before starting off. Never acceler-
ate hard with a cold engine! To see whether or
not the engine is warm, see if it responds to
throttle normally with the stater (choke) turned
off.
WARNING
Before starting off, be sure to turn up or
remove the side stand.
Failure to retract the side stand completely
can result in a serious accident when you
try to turn a corner.
ENGINE BREAK-IN
Brake-in is important to better fit the moving
and sliding parts as well as the installed parts.
It is also important to accustom the rider to the
machine better.
Avoid full-throttle run on a new machine for the
first 5 hours.
After the trial run, check for loose parts, oil
leakage and other problems.
Make full inspection and adjustment especially
of slack cables and drive chain and loose
spokes.
CAUTION:
After the break-in period, check every fit-
ting and fastener for looseness.
If any loose is found, retighten it securely.

SPEC

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EC200000
SPECIFICATIONS
EC211000
GENERAL SPECIFICATIONS
Model name: TT-R90ER (USA, CDN, AUS, NZ)
TT-R90E (Europe, ZA)
Model code number: 5HNE (USA)
5HNF (Europe, AUS, NZ, ZA)
5HNG (CDN)
Dimensions:
Overall length 1,525 mm (57.0 in)
Overall width 605 mm (23.8 in)
Overall height 865 mm (34.1 in)
Seat height 625 mm (24.6 in)
Wheelbase 1,040 mm (40.9 in)
Minimum ground clearance 160 mm (6.3 in)
Basic weight:
With oil and full fuel tank 67 kg (147.7 lb)
Engine:
Engine type Air cooled 4-stroke, SOHC
Cylinder arrangement Single cylinder, forward inclined
Displacement 89 cm
3

(5.43 cu.in)
Bore

×

stroke 47.0
×
51.8 mm (1.85
×
2.04 in)
Compression ratio 8.5 : 1
Compression pressure (STD) 1,000 kPa (10 kg/cm
2

, 145 psi) at 1,000 r/min
Starting system Kick and electric starter
Lubrication system: Wet sump
Oil type or grade:
Engine oil

(For USA and CDN)
At –10 ˚C (10 ˚F) or higher
Å
Yamalube 4 (10W-30) or SAE 10W-30 type
SE/SF motor oil
At 5 ˚C (40 ˚F) or higher
ı
Yamalube 4 (20W-40) or SAE 20W-40 type
SE/SF motor oil
(Except for USA and CDN)
API “SE/SF” or higher grade
0 10 30 50 70 90 110 130
-20 -10 01020
30 40 50
Å
ı
˚F
˚C

GENERAL SPECIFICATIONS

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

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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

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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
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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