2004 YAMAHA TW125 light

INSTRUMENT AND CONTROL FUNCTIONS
3-8
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EAU13600
Starter (choke) knob “”
Starting a cold engine requires a richer
air-fuel mixture, which is supplied by
the starter (choke).
Move the knob in direction (a) to turn on
the starter (choke).
Move the knob in direction (b) to turn off
the starter (choke).
EAU13770
Steering lock
To lock the steering
1. Turn the handlebar all the way to
the right.
2. Open the steering lock cover, and
then insert the steering lock key.
3. Turn the key 1/8 turn counterclock-
wise, push it in while turning the
handlebar slightly to the left, and
then turn the key 1/8 turn clock-
wise.
4. Check that the steering is locked,
remove the key, and then close the
lock cover.
To unlock the steering
1. Open the steering lock cover, and
then insert the steering lock key.
2. Push the key in, turn it 1/8 turn
counterclockwise so that it moves
out, and then release it.
3. Remove the key, and then close
the lock cover.

1. Starter (choke) knob “”
1
(a)
(b)

1. Steering lock cover
2. Steering lock
21

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PRE-OPERATION CHECKS
4-3
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45
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Drive chain

Check chain slack.

Adjust if necessary.

Check chain condition.

Lubricate if necessary.6-21, 6-23
Wheels and tires

Check for damage.

Check tire condition and tread depth.

Check air pressure.

Correct if necessary.6-13, 6-16
Brake and shift pedals

Make sure that operation is smooth.

Lubricate pedal pivoting points if necessary.6-24
Brake and clutch levers

Make sure that operation is smooth.

Lubricate lever pivoting points if necessary.6-24
Sidestand

Make sure that operation is smooth.

Lubricate pivot if necessary.6-25
Chassis fasteners

Make sure that all nuts, bolts and screws are properly tightened.

Tighten if necessary.—
Instruments, lights, signals
and switches

Check operation.

Correct if necessary.—
Sidestand switch

Check operation of ignition circuit cut-off system.

If system is defective, have Yamaha dealer check vehicle.3-11
ITEM CHECKS PAGE

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5-1
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OPERATION AND IMPORTANT RIDING POINTS
EAU15950
WARNING

EWA10270

Become thoroughly familiar
with all operating controls and
their functions before riding.
Consult a Yamaha dealer re-
garding any control or function
that you do not thoroughly un-
derstand.

Never 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.

Before 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.
EAU16060
Starting a cold engine
In order for the ignition circuit cut-off
system to enable starting, one of the
following conditions must be met:

The transmission is in the neutral
position.

The transmission is in gear with
the clutch lever pulled and the sid-
estand up.
WARNING

EWA10290

Before starting the engine,
check the function of the igni-
tion circuit cut-off system ac-
cording to the procedure
described on page 3-11.

Never 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 neu-
tral position.
NOTE:

When the transmission is in the neutral
position, the neutral indicator light
should be on, otherwise have a
Yamaha dealer check the electrical cir-
cuit.
4. Turn the starter (choke) on and
completely close the throttle. (See
page 3-8.)
5. Start the engine by pushing the
start switch.
NOTE:

If the engine fails to start, release the
start switch, wait a few seconds, and
then try again. Each starting attempt
should be as short as possible to pre-
serve the battery. Do not crank the en-
gine more than 10 seconds on any one
attempt.
6. After starting the engine, move the
starter (choke) back halfway.
CAUTION:

ECA11040
For maximum engine life, never ac-
celerate hard when the engine is

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OPERATION AND IMPORTANT RIDING POINTS
5-2
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cold!
7. When the engine is warm, turn the
starter (choke) off.
NOTE:

The engine is warm when it responds
normally to the throttle with the starter
(choke) turned off.
EAU16640
Starting a warm engine
Follow the same procedure as for start-
ing a cold engine with the exception
that the starter (choke) is not required
when the engine is warm.
EAU16671
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 il-
lustration.
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.
1. Shift pedal
2. Neutral position
1
N5
4
3
2
1
2

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OPERATION AND IMPORTANT RIDING POINTS
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CAUTION:

ECA10260

Even 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 dis-
tances. The transmission is
properly lubricated only when
the engine is running. Inade-
quate lubrication may damage
the transmission.

Always use the clutch while
changing gears to avoid damag-
ing the engine, transmission,
and drive train, which are not
designed to withstand the
shock of forced shifting.
EAU32810
Recommended shift points (for
Switzerland only)
The recommended shift points during
acceleration are shown in the table be-
low.
NOTE:

When shifting down two gears at a
time, reduce the speed accordingly
[e.g., down to 35 km/h (22 mi/h) when
shifting from 4th to 2nd gear].
EAU16800
Tips for reducing fuel
consumption
Fuel consumption depends largely on
your riding style. Consider the following
tips to reduce fuel consumption:

Turn the starter (choke) off as
soon as possible.

Shift up swiftly, and avoid high en-
gine speeds during acceleration.

Do not rev the engine while shifting
down, and avoid high engine
speeds with no load on the engine.

Turn the engine off instead of let-
ting it idle for an extended length of
time (e.g., in traffic jams, at traffic
lights or at railroad crossings).
Shift up points:
1st
→
2nd: 23 km/h (14 mi/h)
2nd
→
3rd: 36 km/h (22 mi/h)
3rd
→
4th: 50 km/h (31 mi/h)
4th
→
5th: 60 km/h (37 mi/h)

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PERIODIC MAINTENANCE AND MINOR REPAIR
6-4
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EAU18660
NOTE:


The air filter needs more frequent service if you are riding in unusually wet or dusty areas.

Hydraulic brake service

Regularly check and, if necessary, correct the brake fluid level.

Every two years replace the internal components of the brake master cylinder and caliper, and change the brake fluid.

Replace the brake hoses every four years and if cracked or damaged.
25

*
Front and rear brake
switches

Check operation.
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26

Moving parts and cables

Lubricate.
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27

*
Throttle grip housing
and cable

Check operation and free play.

Adjust the throttle cable free play if necessary.

Lubricate the throttle grip housing and cable.
√

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√

√


28

*
Lights, signals and
switches

Check operation.

Adjust headlight beam.
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√

NO. ITEM CHECK OR MAINTENANCE JOBODOMETER READING (
×× × ×
1000 km)
ANNUAL
CHECK
1 6 12 18 24

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PERIODIC MAINTENANCE AND MINOR REPAIR
6-6
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To install the panel
Place the panel in the original position.

EAU19602
Checking the spark plug
The spark plug is an important engine
component, which is easy to check.
Since heat and deposits will cause any
spark plug to slowly erode, the spark
plug should be removed and checked
in accordance with the periodic mainte-
nance and lubrication chart. In addition,
the condition of the spark plug can re-
veal the condition of the engine.
To remove the spark plug
1. Remove the spark plug cap.
2. Remove the spark plug as shown,
with the spark plug wrench includ-
ed in the owner’s tool kit.
To check the spark plug
1. Check that the porcelain insulator
around the center electrode of the
spark plug is a medium-to-light tan
(the ideal color when the vehicle is
ridden normally).
NOTE:

If the spark plug shows a distinctly dif-
ferent color, the engine could be defec-
tive. Do not attempt to diagnose such
problems yourself. Instead, have a
Yamaha dealer check the vehicle.
2. Check the spark plug for electrode
erosion and excessive carbon or
other deposits, and replace it if
1. Spark plug cap
1

1. Spark plug wrench
1

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PERIODIC MAINTENANCE AND MINOR REPAIR
6-7
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necessary.
To install the spark plug
1. Measure the spark plug gap with a
wire thickness gauge and, if nec-
essary, adjust the gap to specifica-
tion.
2. Clean the surface of the spark plug
gasket and its mating surface, and
then wipe off any grime from the
spark plug threads.3. Install the spark plug with the
spark plug wrench, and then tight-
en it to the specified torque.
NOTE:

If a torque wrench is not available when
installing a spark plug, a good estimate
of the correct torque is 1/4–1/2 turn
past finger tight. However, the spark
plug should be tightened to the speci-
fied torque as soon as possible.
4. Install the spark plug cap.
EAU19792
Engine oil and oil filter
element
The engine oil level should be checked
before each ride. In addition, the oil
must be changed and the oil filter ele-
ment cleaned at the intervals specified
in the periodic maintenance and lubri-
cation chart.
To check the engine oil level
1. Place the vehicle on a level sur-
face and hold it in an upright posi-
tion.
NOTE:

Make sure that the vehicle is positioned
straight up when checking the oil level.
A slight tilt to the side can result in a
false reading.
2. Start the engine, warm it up for
several minutes, and then turn it
off.
3. Wait a few minutes until the oil set-
tles, and then check the oil level
through the check window located
at the bottom-right side of the Specified spark plug:
NGK/DR8EA
1. Spark plug gap
Spark plug gap:
0.6–0.7 mm (0.024–0.028 in)
1

Tightening torque:
Spark plug:
17.5 Nm (1.75 m·kgf,
12.7 ft·lbf)

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