2003 YAMAHA TW125 transmission

3-2
INSTRUMENT AND CONTROL FUNCTIONS
3
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Speedometer unit
The speedometer unit is equipped
with a speedometer, an odometer
and a tripmeter. The speedometer
shows riding speed. The odometer
shows the total distance traveled.
The tripmeter shows the distance
traveled since it was last set to zero
with the reset knob. The tripmeter
can be used to estimate the distance
that can be traveled with a full tank of
fuel. This information will enable you
to plan future fuel stops.
4
12
3
1. Speedometer
2. Odometer
3. Tripmeter
4. Reset knob
NOTE:
Only for the German model equipped
with a speed limiter:
The speed limiter prevents the motor-
cycle from exceeding a riding speed
of 80 km/h.
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Neutral indicator light “N”
This indicator light comes on when
the transmission is in the neutral
position.
312
1. Turn signal indicator light “5”
2. High beam indicator light “&”
3. Neutral indicator light “N”
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3-4
INSTRUMENT AND CONTROL FUNCTIONS
3
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Clutch lever
The clutch lever is located at the left
handlebar grip. To disengage the
clutch, pull the lever toward the han-
dlebar grip. To engage the clutch,
release the lever. The lever should
be pulled rapidly and released slowly
for smooth clutch operation.
The clutch lever is equipped with a
clutch switch, which is part of the igni-
tion circuit cut-off system. (See page
3-12 for an explanation of the ignition
circuit cut-off system.)
1
1. Clutch lever
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Shift pedal
The shift pedal is located on the left
side of the engine and is used in
combination with the clutch lever
when shifting the gears of the
5-speed constant-mesh transmission
equipped on this motorcycle.
1
1. Shift pedal
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Start switch “,”
Push this switch to crank the engine
with the starter.
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See page 5-1 for starting instruc-
tions prior to starting the engine.
1
2
1. Engine stop switch “#/$”
2. Start switch “,”
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3-12
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Ignition circuit cut-off
system
The ignition circuit cut-off system
(comprising the sidestand switch,
clutch switch and neutral switch) has
the following functions.
8It prevents starting when the
transmission is in gear and the
sidestand is up, but the clutch
lever is not pulled.
8It prevents starting when the
transmission is in gear and the
clutch lever is pulled, but the
sidestand is still down.
8It cuts the running engine when
the transmission is in gear and
the sidestand is moved down.
Periodically check the operation of
the ignition circuit cut-off system
according to the following procedure.
EW000045
w
If a malfunction is noted, have a
Yamaha dealer check the system
before riding.
INSTRUMENT AND CONTROL FUNCTIONS
3
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3-13
INSTRUMENT AND CONTROL FUNCTIONS
3
With the engine turned off:
1. Move the sidestand down.
2. Make sure that the engine stop switch is set to “
#”.
3. Turn the key to “ON”.
4. Shift the transmission into the neutral position.
5. Push the start switch.
Does the engine start?
The neutral switch may be defective.
The motorcycle should not be ridden until
checked by a Yamaha dealer.
With the engine still running:
6. Move the sidestand up.
7. Keep the clutch lever pulled.
8. Shift the transmission into gear.
9. Move the sidestand down.
Does the engine stall?
After the engine has stalled:
10. Move the sidestand up.
11. Keep the clutch lever pulled.
12. Push the start switch.
Does the engine start?
The sidestand switch may be defective.
The motorcycle should not be ridden until
checked by a Yamaha dealer.
The clutch switch may be defective.
The motorcycle should not be ridden until
checked by a Yamaha dealer.
NO
NOTE:
This check is most reliable if performed with
a warmed-up engine.
YES
YES NO
The system is OK. The motorcycle can be ridden.
YES NO
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5-1
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OPERATION AND IMPORTANT RIDING POINTS
5
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8Become thoroughly familiar
with all operating controls and
their functions before riding.
Consult a Yamaha dealer
regarding any control or func-
tion that you do not thorough-
ly understand.
8Never start the engine or oper-
ate it in a closed area for any
length of time. Exhaust fumes
are poisonous, and inhaling
them can cause loss of con-
sciousness and death within a
short time. Always make sure
that there is adequate ventila-
tion.
8Before starting out, make sure
that the sidestand is up. If the
sidestand is not raised com-
pletely, it could contact the
ground and distract the opera-
tor, resulting in a possible loss
of control.
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Starting a cold engine
In order for the ignition circuit cut-off
system to enable starting, one of the
following conditions must be met:
8The transmission is in the neutral
position.
8The transmission is in gear with
the clutch lever pulled and the
sidestand up.
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w
8Before starting the engine,
check the function of the igni-
tion circuit cut-off system
according to the procedure
described on page 3-13.
8Never ride with the sidestand
down.
1. Turn the fuel cock lever to “ON”.
2. Turn the key to “ON” and make
sure that the engine stop switch
is set to “#”.
3. Shift the transmission into the
neutral position.
NOTE:
When the transmission is in the neu-
tral position, the neutral indicator light
should be on, otherwise have a
Yamaha dealer check the electrical
circuit.
ONFUEL
RES
OFF
1ON
1. Arrow mark positioned over “ON”
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5-3
OPERATION AND IMPORTANT RIDING POINTS
5
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Shifting
Shifting gears lets you control the
amount of engine power available for
starting off, accelerating, climbing
hills, etc.
The gear positions are shown in the
illustration.
NOTE:
To shift the transmission into the neu-
tral position, press the shift pedal
down repeatedly until it reaches the
end of its travel, and then slightly
raise it.
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8Even with the transmission in
the neutral position, do not
coast for long periods of time
with the engine off, and do not
tow the motorcycle for long
distances. The transmission is
properly lubricated only when
the engine is running.
Inadequate lubrication may
damage the transmission.
8Always use the clutch while
changing gears to avoid dam-
aging the engine, transmis-
sion, and drive train, which are
not designed to withstand the
shock of forced shifting.
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Recommended shift points
(for Switzerland only)
The recommended shift points during
acceleration are shown in the table
below.
NOTE:
When shifting down two gears at a
time, reduce the speed accordingly
(e.g., down to 35 km/h when shifting
from 4th to 2nd gear).
1
N5
4
3
2
1
1. Shift pedal
N. Neutral position
Shift point
(km/h)
1st→2nd
2nd→3rd
3rd→4th
4th→5th23
36
50
60
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6-25
PERIODIC MAINTENANCE AND MINOR REPAIR
6
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Changing the brake fluid
Have a Yamaha dealer change the
brake fluid at the intervals specified in
the NOTE after the periodic mainte-
nance and lubrication chart. In addi-
tion, have the oil seals of the brake
master cylinder and caliper as well as
the brake hose replaced at the inter-
vals listed below or whenever they
are damaged or leaking.
8Oil seals: Replace every two
years.
8Brake hose: Replace every four
years.
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Drive chain slack
The drive chain slack should be
checked before each ride and adjust-
ed if necessary.
To check the drive chain slack
1. Place the motorcycle on a level
surface and hold it in an upright
position.
NOTE:
When checking and adjusting the
drive chain slack, the motorcycle
should be positioned straight up and
there should be no weight on it.2. Shift the transmission into the
neutral position.
3. Move the rear wheel by pushing
the motorcycle to locate the tight-
est portion of the drive chain,
and then measure the drive
chain slack as shown.
4. If the drive chain slack is incor-
rect, adjust it as follows.
a
a. Drive chain slack
Drive chain slack:
35–60 mm
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8-2
SPECIFICATIONS
8
Air filterWet type element
Fuel
Type REGULAR UNLEADED
GASOLINE ONLY
Fuel tank capacity 7.0 L
Reserve amount 1.7 L
Carburetor
Manufacturer TEIKEI
Model ×quantity MV28 ×1
Spark plug
Manufacturer/Type NGK/DR8EA
Gap 0.6–0.7 mm
Clutch typeWet, multiple-disc
Transmission
Primary reduction system Spur gear
Primary reduction ratio 74/20 (3.700)
Secondary reduction system Chain drive
Secondary reduction ratio 3.643
Number of drive chain
sprocket teeth (rear/front) 51/14
Transmission type Constant mesh 5-speed
Operation Left foot operationGear ratio 1st 2.250
2nd 1.476
3rd 1.125
4th 0.926
5th 0.793
Chassis
Frame type Diamond
Caster angle 25.83°
Trail 93 mm
Tires
Front
Type With tube
Size 130/80-18 M/C 66P
Manufacturer/ BRIDGESTONE/TW-203
model
Rear
Type With tube
Size 180/80-14 M/C 78P
Manufacturer/ BRIDGESTONE/TW-204
model
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