2002 YAMAHA TW125 ignition

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TABLE OF CONTENTS
GIVE SAFETY THE RIGHT OF WAY ............... 1-1
DESCRIPTION ................................................. 2-1
Left view ......................................................... 2-1
Right view ...................................................... 2-2
Controls and instruments ............................... 2-3
INSTRUMENT AND CONTROL FUNCTIONS . 3-1
Main switch .................................................... 3-1
Indicator lights ................................................ 3-1
Speedometer unit .......................................... 3-2
Handlebar switches ........................................ 3-2
Clutch lever .................................................... 3-4
Shift pedal ...................................................... 3-4
Brake lever ..................................................... 3-4
Brake pedal .................................................... 3-5
Fuel tank cap ................................................. 3-5
Fuel ................................................................ 3-6
Fuel cock ........................................................ 3-7
Starter (choke) knob ...................................... 3-8
Steering lock .................................................. 3-8
Seat ................................................................ 3-9
Helmet holder ................................................. 3-9
Shock absorber ............................................ 3-10
Carrier .......................................................... 3-10
Luggage strap holders ................................. 3-10
Sidestand ..................................................... 3-11Ignition circuit cut-off system ........................ 3-11
PRE-OPERATION CHECKS ............................ 4-1
Pre-operation check list ................................. 4-1
OPERATION AND IMPORTANT RIDING
POINTS ............................................................. 5-1
Starting the engine ......................................... 5-1
Starting a warm engine .................................. 5-2
Shifting ........................................................... 5-3
Recommended shift points
(for Switzerland only) .................................. 5-3
Tips for reducing fuel consumption ................ 5-4
Engine break-in .............................................. 5-4
Parking ........................................................... 5-5
PERIODIC MAINTENANCE AND MINOR
REPAIR ............................................................. 6-1
Owner’s tool kit .............................................. 6-1
Periodic maintenance and lubrication chart ... 6-2
Removing and installing panels ..................... 6-5
Checking the spark plug ................................ 6-7
Engine oil and oil filter element ...................... 6-9
Cleaning the air filter element and check
hose .......................................................... 6-12
Adjusting the carburetor ............................... 6-14
Adjusting the engine idling speed ................ 6-14
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3-1
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INSTRUMENT AND CONTROL FUNCTIONS
3
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Main switchMain switchThe main switch controls the ignition
and lighting systems. The various
main switch positions are described
below.
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ON
All electrical systems are supplied
with power, and the engine can be
started. The key cannot be removed.
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OFF
All electrical systems are off. The key
can be removed.
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Neutral indicator light “N”
This indicator light comes on when
the transmission is in the neutral
position.
OFFON
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Indicator lights
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Turn signal indicator light “
5”
This indicator light flashes when the
turn signal switch is pushed to the left
or right.
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High beam indicator light “&”
This indicator light comes on when
the high beam of the headlight is
switched on.
3
12
1. Turn signal indicator light “5”
2. High beam indicator light “&”
3. Neutral indicator light “N”
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3-4
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Clutch leverThe 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
3-11 for an explanation of the ignition
circuit cut-off system.)INSTRUMENT AND CONTROL FUNCTIONS
3
1
1. Clutch lever
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Brake leverThe brake lever is located at the right
handlebar grip. To apply the front
brake, pull the lever toward the han-
dlebar grip.
1
1. Brake lever
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Shift pedalThe 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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3-11
INSTRUMENT AND CONTROL FUNCTIONS
3
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SidestandThe sidestand is located on the left
side of the frame. Raise the side-
stand or lower it with your foot while
holding the motorcycle upright.NOTE:
The built-in sidestand switch is part of
the ignition circuit cut-off system,
which cuts the ignition in certain situ-
ations. (See further down for an
explanation of the ignition circuit cut-
off system.)
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Ignition circuit cut-off
systemThe 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.
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wIf a malfunction is noted, have a
Yamaha dealer check the system
before riding.
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wThe motorcycle must not be ridden
with the sidestand down, or if the
sidestand cannot be properly
moved up (or does not stay up),
otherwise the sidestand could con-
tact the ground and distract the
operator, resulting in a possible
loss of control. Yamaha’s ignition
circuit cut-off system has been
designed to assist the operator in
fulfilling the responsibility of rais-
ing the sidestand before starting
off. Therefore, check this system
regularly as described below and
have a Yamaha dealer repair it if it
does not function properly.
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4-3
PRE-OPERATION CHECKS
4
NOTE:
Pre-operation checks should be made each time the motorcycle is used. Such an inspection can be accomplished in a
very short time; and the added safety it assures is more than worth the time involved.
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wIf any item in the Pre-operation check list is not working properly, have it inspected and repaired before operat-
ing the motorcycle.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.3-1–3-3, 6-34–6-37
Sidestand switch•Check operation of ignition circuit cut-off system.
•If system is defective, have Yamaha dealer check vehicle.3-11–3-12 ITEM CHECKS PAGE
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5-1
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OPERATION AND IMPORTANT RIDING POINTS
5
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w8Become 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 the engineIn 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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w8Before starting the engine,
check the function of the igni-
tion circuit cut-off system
according to the procedure
described on page 3-12.
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.
ON
FUEL
RES
OFF
1
ON
1. Arrow mark positioned over “ON”
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6-42
PERIODIC MAINTENANCE AND MINOR REPAIR
6
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wAfter adjusting the brake pedal
free play, check the operation of
the brake light.
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TroubleshootingAlthough Yamaha motorcycles
receive a thorough inspection before
shipment from the factory, trouble
may occur during operation. Any
problem in the fuel, compression, or
ignition systems, for example, can
cause poor starting and loss of
power.
The following troubleshooting chart
represents a quick and easy proce-
dure for checking these vital systems
yourself. However, should your
motorcycle require any repair, take it
to a Yamaha dealer, whose skilled
technicians have the necessary tools,
experience, and know-how to service
the motorcycle properly.
Use only genuine Yamaha replace-
ment parts. Imitation parts may look
like Yamaha parts, but they are often
inferior, have a shorter service life
and can lead to expensive repair
bills.
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6-43
PERIODIC MAINTENANCE AND MINOR REPAIR
6
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Troubleshooting chart
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wKeep away open flames and do not smoke while checking or working on the fuel system.Check the fuel level in
the fuel tank.1. Fuel
There is enough fuel.
There is no fuel.
Check the compression.
Supply fuel.
The engine does not start.
Check the compression.
Operate the electric starter.2. Compression
There is compression.
There is no compression.
Check the ignition.
Have a Yamaha dealer
check the vehicle.
Remove the spark plug
and check the electrodes.3. Ignition
Wipe off with a dry cloth and correct the
spark plug gap, or replace the spark plug.
Have a Yamaha dealer check the vehicle.
The engine does not start.
Have a Yamaha dealer
check the vehicle.
The engine does not start.
Check the battery.
Operate the electric starter.4. Battery
The engine turns over
quickly.
The engine turns over
slowly.
The battery is good.Check the battery lead connections,
and charge the battery if necessary.
DryWet
Open the throttle halfway and operate
the electric starter.
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