2002 YAMAHA TTR90 brake

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GEN
INFO
DESCRIPTION
EC100000
GENERAL INFORMATION
EC110000
DESCRIPTION
1“ENGINE STOP” button
2Front brake lever
3Throttle grip
4Fuel tank cap
5Kick starter
6Fuel tank
7Air cleaner
8Rear brake pedal
9Fuel cock
0Starter lever (choke)
ADrive chain
BShift pedal
CFront fork
NOTE:
lThe machine you have purchased may differ
slightly from those shown in the following.
lDesigns and specifications are subject to
change without notice.
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1

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GEN
INFO
CONTROL FUNCTIONS
EC150000
CONTROL FUNCTIONS
“ENGINE STOP” SWITCH
Make sure that the engine stop switch 1 is
positioned to “ ”. The engine stop switch has
been equipped to ensure safety in an emer-
gency such when the machine is up set or
trouble takes place in the throttle system. The
engine will not start or run when the engine
stop switch is turned to “ ”.
SHIFT PEDAL
The gear ratios of the constant-mesh 3 speed
transmission are ideally spaced. The gears
can be shifted by using the shift pedal 1 on
the left side of the engine.
WARNING
When starting out on the machine, shift the
transmission into 1st after pulling in the
front brake lever and closing the throttle
grip.
KICK STARTER
WARNING
Before starting the engine, be sure to shift
the transmission into neutral.
Rotate the kick starter 1 away from the
engine. Push the starter down lightly with your
foot until the gears engage, then kick smoothly
and forcefully to start the engine.
EC155001
THROTTLE GRIP
The throttle grip 1 is located on the right han-
dlebar; it accelerates or decelerates the
engine. For acceleration, turn the grip toward
you; for deceleration, turn it away from you.

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GEN
INFO
CONTROL FUNCTIONS
EC156000
FRONT BRAKE LEVER
The front brake lever 1 is located on the right
handlebar. Pull it toward the handlebar to acti-
vate the front brake.
EC157000
REAR BRAKE PEDAL
The rear brake pedal 1 is located on the right
side of the machine. Press down on the brake
pedal to activate the rear brake.
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.

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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.
1. Turn the fuel cock to “ON”.
2. Operate the starter (choke) and com-
pletely close the throttle grip.
3. Slide the “ENGINE STOP” switch to the
“”.
4. Kick the kick starter with full strength to
start the engine.
5. 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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Brake:
Front brake type Drum brake
Operation Right hand operation
Rear brake type Drum brake
Operation Right foot operation
Suspension:
Front suspension Telescopic fork
Rear suspension Swingarm (monocross suspension)
Shock absorber:
Front shock absorber Coil spring/oil damper
Rear shock absorber Coil spring/gas, oil damper
Wheel travel:
Front wheel travel 110 mm (4.33 in)
Rear wheel travel 93 mm (3.66 in)
Electrical:
Ignition system CDI magneto
GENERAL SPECIFICATIONS

SPEC
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Drum brake:
Front drum brake type Leading, trailing ----
Rear drum brake type Leading, trailing ----
Front drum inside diameter 95 mm (3.74 in) 96 mm (3.78 in)
Rear drum inside diameter 110 mm (4.33 in) 111 mm (4.37 in)
Front lining thickness 3 mm (0.12 in) 2 mm (0.08 in)
Rear lining thickness 4 mm (0.16 in) 2 mm (0.08 in)
Front shoe spring free length 32.7 mm (1.29 in) ----
Rear shoe spring free length 50.5 mm (1.99 in) ----
Brake lever and brake pedal:
Brake lever free play (lever end) 10 ~ 20 mm (0.39 ~ 0.79 in) ----
Brake pedal free play 10 ~ 20 mm (0.39 ~ 0.79 in) ----
Throttle grip free play 3 ~ 5 mm (0.12 ~ 0.20 in) ----Item Standard Limit
MAINTENANCE SPECIFICATIONS

SPEC
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NOTE:
l1. 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).
l-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 40 4.0 29
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) M6 ´ 1.0 4 13 1.3 9.4
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
Chain case M5 ´ 0.8 5 4 0.4 2.9
Chain puller locknut M6 ´ 1.0 2 3 0.3 2.2
Footrest and frame M8 ´ 1.25 2 30 3.0 22
MAINTENANCE SPECIFICATIONS

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SPECCABLE ROUTING DIAGRAM
CABLE ROUTING DIAGRAM
1Crankcase breather hose
2Wire harness
3CDI magneto lead
4Starter cable
5Carburetor heating lead
6Engine stop switch lead
7Thermo switch
8Thermo switch lead
9Spark plug lead
0Throttle cableACable holder
BFuel tank breather hose
CBrake cable
After fastening the starter cable, CDI magneto lead, wire harness and
thermo switch lead, cut off any excess from the plastic locking tie end.
õPass the ignition coil lead through the lead guide.
‚Fasten the engine stop switch lead with the plastic bands.
ëPass the brake cable through the cable guides.
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9
0
B A
6
C 1
õ
‚
ë
ë
A
A
67
8
20 ~ 30 mm
(0.79 ~ 1.18 in)