2002 YAMAHA DT125R transmission

PERIODIC MAINTENANCE AND
MINOR REPAIR ................................................ 6-1
Owner’s tool kit ............................................... 6-1
Periodic maintenance and lubrication chart ... 6-2
Removing and installing cowlings .................. 6-5
Removing and installing panels ...................... 6-7
Checking the spark plug ................................. 6-9
Transmission oil ........................................... 6-10
Coolant ......................................................... 6-12
Changing the coolant ................................... 6-14
Cleaning the air filter element........................ 6-16
Adjusting the carburetor ............................... 6-17
Adjusting the engine idling speed ................ 6-17
Adjusting the throttle cable free play ............ 6-18
Tires ............................................................. 6-19
Spoke wheels ............................................... 6-21
Adjusting the clutch lever free play ............... 6-22
Adjusting the brake lever free play ............... 6-23
Adjusting the brake pedal position ............... 6-23
Adjusting the rear brake light switch ............. 6-24
Checking the front and rear brake pads ....... 6-24
Checking the brake fluid level ...................... 6-25
Changing the brake fluid .............................. 6-26
Drive chain slack .......................................... 6-27
Lubricating the drive chain ........................... 6-28
Checking and lubricating the cables ............. 6-29Checking and lubricating the
throttle grip and cable ................................ 6-29
Adjusting the Autolube pump ....................... 6-30
Checking and lubricating the brake and
shift pedals ................................................ 6-30
Checking and lubricating the brake and
clutch levers .............................................. 6-30
Checking and lubricating the sidestand ....... 6-31
Checking the front fork ................................. 6-31
Checking the steering ................................... 6-32
Checking the wheel bearings ....................... 6-32
Battery .......................................................... 6-33
Replacing the fuse ....................................... 6-35
Replacing the headlight bulb ........................ 6-36
Replacing a turn signal light bulb ................. 6-37
Replacing the tail/brake light bulb ................ 6-38
Supporting the motorcycle ............................ 6-39
Front wheel ................................................... 6-39
Rear wheel ................................................... 6-42
Troubleshooting ............................................ 6-43
Troubleshooting charts ................................. 6-44
MOTORCYCLE CARE AND STORAGE ........... 7-1
Care ................................................................ 7-1
Storage ........................................................... 7-4
TABLE OF CONTENTS6
7
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3-1
EAU00027
INSTRUMENT AND CONTROL FUNCTIONS
3
EAU00028
Main switchThe main switch controls the ignition
and lighting systems. The various
main switch positions are described
below.
EAU00036
ON
All electrical systems are supplied
with power, and the engine can be
started. The key cannot be removed.
EAU00038
OFF
All electrical systems are off. The key
can be removed.
EAU00061
Neutral indicator light “N”
This indicator light comes on when
the transmission is in the neutral
position.
EAU04258
2-stroke engine oil level warning
light “
7
”
This warning light comes on when
the 2-stroke engine oil level is low.
The electrical circuit of the warning
light can be checked according to the
following procedure.
1. Turn the key to “ON”.
2. Shift the transmission into the
neutral position.
3. If the warning light does not
come on, have a Yamaha dealer
check the electrical circuit.
NOTE:
Even if the 2-stroke engine oil level is
sufficient, the warning light may flick-
er when riding on a slope or during
sudden acceleration or deceleration,
but this is not a malfunction.
ON
OFF
EAU03034
Indicator and warning lights
EAU00057
Turn signal indicator light “5”
This indicator light flashes when the
turn signal switch is pushed to the left
or right.
EAU00063
High beam indicator light “&”
This indicator light comes on when
the high beam of the headlight is
switched on.
1
2
3
4
1. Turn signal indicator light “5”
2. High beam indicator light “&”
3. Neutral indicator light “N”
4. 2-stroke engine oil level warning
light “
7
”
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3-4
EAU03890
Engine stop switch “#/$”
Set this switch to “#” before starting
the engine. Set this switch to “$” to
stop the engine in case of an emer-
gency, such as when the motorcycle
overturns or when the throttle cable is
stuck.INSTRUMENT AND CONTROL FUNCTIONS
3
1
1. Engine stop switch “#/$”
EAU00155
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.
1
1. Clutch lever
EAU00157
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
6-speed constant-mesh transmission
equipped on this motorcycle.
1
1. Shift pedal
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3-10
INSTRUMENT AND CONTROL FUNCTIONS
3
EAU03839
Starter (choke) lever“1”Starting a cold engine requires a rich-
er air-fuel mixture, which is supplied
by the starter (choke).
Move the lever in direction ato turn
on the starter (choke).
Move the lever in direction bto turn
off the starter (choke).
a
b
1
1. Starter (choke) lever “1”
EAU00212
KickstarterTo start the engine, fold out the kick-
starter lever, move it down lightly with
your foot until the gears engage, and
then push it down smoothly but force-
fully. This model is equipped with a
primary kickstarter, allowing the
engine to be started in any gear if the
clutch is disengaged. However, shift-
ing the transmission into the neutral
position before starting is recom-
mended.
1
1. Kickstarter
EAU02934
Steering lockTo lock the steering
1. Turn the handlebar all the way to
the right.
2. Open the steering lock cover,
and then insert the key.
3. Turn the key 1/8 turn counter-
clockwise, push it in while turning
the handlebar slightly to the left,
and then turn the key 1/8 turn
clockwise.
4. Check that the steering is locked,
remove the key, and then close
the lock cover.
2
1
1. Steering lock cover
2. Steering lock
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3-16
EAU03571
Ignition circuit cut-off
systemThe ignition circuit cut-off system
(comprising the sidestand switch and
neutral switch) has the following func-
tions.
8It prevents starting when the
transmission is in gear and 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
wIf a malfunction is noted, have a
Yamaha dealer check the system
before riding.INSTRUMENT AND CONTROL FUNCTIONS
3 3MB-9-E8 6/13/01 10:55 AM Page 28

3-17
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 kickstarter lever down.
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?
The sidestand 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.
YESYES NO
The system is OK. The motorcycle can be ridden.
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4-1
EAU01114
PRE-OPERATION CHECKS
4The condition of a vehicle is the owner’s responsibility. Vital components can start to deteriorate quickly and unexpect-
edly, even if the vehicle remains unused (for example, as a result of exposure to the elements). Any damage, fluid leak-
age or loss of tire air pressure could have serious consequences. Therefore, it is very important, in addition to a thor-
ough visual inspection, to check the following points before each ride.
EAU03439
Pre-operation check list
ITEM CHECKS PAGE
Fuel•Check fuel level in fuel tank.
•Refuel if necessary.
•Check fuel line for leakage.3-5–3-7
2-stroke engine oil•Check oil level in oil tank.
•If necessary, add recommended oil to specified level.
•Check vehicle for oil leakage.3-8
Transmission oil•Check oil level in transmission case.
•If necessary, add recommended oil to specified level.6-10–6-12
Coolant•Check coolant level in reservoir.
•If necessary, add recommended coolant to specified level.
•Check cooling system for leakage.6-12–6-15
Front brake•Check operation.
•If soft or spongy, have Yamaha dealer bleed hydraulic system.
•Check lever free play.
•Adjust if necessary.
•Check fluid level in reservoir.
•If necessary, add recommended brake fluid to specified level.
•Check hydraulic system for leakage.3-5, 6-23, 6-24–6-26
Rear brake•Check operation.
•If soft or spongy, have Yamaha dealer bleed hydraulic system.
•Check fluid level in reservoir.
•If necessary, add recommended brake fluid to specified level.
•Check hydraulic system for leakage.3-5, 6-23–6-26
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5-1
EAU00372
OPERATION AND IMPORTANT RIDING POINTS
5
EAU00373
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.
EAU01177
Starting a cold 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.
EW000054
w8Before starting the engine,
check the function of the igni-
tion circuit cut-off system
according to the procedure
described on page 3-17.
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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