2002 YAMAHA DT125R service

3-13
INSTRUMENT AND CONTROL FUNCTIONS
3 3. Tighten the locknut to the speci-
fied torque.
EC000018
cCAlways tighten the locknut against
the adjusting nut, and then tighten
the locknut to the specified torque.
EAU00315
wThis shock absorber contains
highly pressurized nitrogen gas.
For proper handling, read and
understand the following informa-
tion before handling the shock
absorber. The manufacturer can-
not be held responsible for proper-
ty damage or personal injury that
may result from improper han-
dling.
8Do not tamper with or attempt
to open the gas cylinder.
8Do not subject the shock
absorber to an open flame or
other high heat sources, other-
wise it may explode due to
excessive gas pressure.
8Do not deform or damage the
gas cylinder in any way, as
this will result in poor damp-
ing performance.
8Always have a Yamaha dealer
service the shock absorber.
NOTE:
The spring preload setting is deter-
mined by measuring distance A,
shown in the illustration. The shorter
distance A is, the lower the spring
preload; the longer distance A is, the
higher the spring preload.
A
Spring preload:
Minimum (soft):
Distance A = 235 mm
Standard:
Distance A = 230 mm
Maximum (hard):
Distance A = 220 mm
Tightening torque:
Locknut:
55 Nm (5.5 m0kgf)
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6-1
EAU00462
PERIODIC MAINTENANCE AND MINOR REPAIR
6
EAU00464
Safety is an obligation of the owner.
Periodic inspection, adjustment and
lubrication will keep your vehicle in
the safest and most efficient condi-
tion possible. The most important
points of inspection, adjustment, and
lubrication are explained on the fol-
lowing pages.
The intervals given in the periodic
maintenance and lubrication chart
should be simply considered as a
general guide under normal riding
conditions. However, DEPENDING
ON THE WEATHER, TERRAIN,
GEOGRAPHICAL LOCATION, AND
INDIVIDUAL USE, THE MAINTE-
NANCE INTERVALS MAY NEED TO
BE SHORTENED.
EW000060
wIf you are not familiar with motor-
cycle maintenance work, have a
Yamaha dealer do it for you.
EAU01175
Owner’s tool kitThe owner’s tool kit is located behind
panel B. (See page 6-8 for panel
removal and installation procedures.)
The service information included in
this manual and the tools provided in
the owner’s tool kit are intended to
assist you in the performance of pre-
ventive maintenance and minor
repairs. However, additional tools
such as a torque wrench may be nec-
essary to perform certain mainte-
nance work correctly.
1
1. Owner’s tool kit
NOTE:
If you do not have the tools or experi-
ence required for a particular job,
have a Yamaha dealer perform it for
you.
EW000063
wModifications not approved by
Yamaha may cause loss of perfor-
mance and render the vehicle
unsafe for use. Consult a Yamaha
dealer before attempting any
changes.
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6-4
PERIODIC MAINTENANCE AND MINOR REPAIR
6
EAU03884
NOTE:
8The air filter needs more frequent service if you are riding in unusually wet or dusty areas.
8Hydraulic brake service
9Regularly check and, if necessary, correct the brake fluid level.
9Every two years replace the internal components of the brake master cylinders and calipers, and change the
brake fluid.
9Replace the brake hoses every four years and if cracked or damaged.21
*Carburetor•Check starter (choke) operation.
•Adjust engine idling speed.√√√√√ √
22*Autolube pump•Check operation.
•Bleed if necessary.√√√√
23 Transmission oil•Check oil level.√√√√√ √
•Change.√√
24*Cooling system•Check coolant level and vehicle for coolant leakage.√√√√ √
•Change.Every 3 years
25*Front and rear brake
switches•Check operation.√√√√√ √
26 Moving parts and cables•Lubricate.√√√√ √
27*Lights, signals and
switches•Check operation.
•Adjust headlight beam.√√√√√ √ NO. ITEM CHECK OR MAINTENANCE JOBODOMETER READING (× 1,000 km)
ANNUAL
CHECK
1 6 12 18 24
3MB-9-E8 6/13/01 10:55 AM Page 41

6-17
PERIODIC MAINTENANCE AND MINOR REPAIR
67. Pull the sponge material over the
frame.
8. Install the air filter element onto
the guide, and then tighten the
wing nut.
9. Insert the air filter element into
the case.
10. Install the air filter case cover by
installing the screws.
11. Install the panel.
EC000082
cC8Make sure that the air filter ele-
ment is properly seated in the
air filter case.
8The engine should never be
operated without the air filter
element installed, otherwise
the piston and/or cylinder may
become excessively worn.
EAU00632
Adjusting the engine idling
speedThe engine idling speed must be
checked and, if necessary, adjusted
as follows at the intervals specified in
the periodic maintenance and lubrica-
tion chart.
1. Start the engine and warm it up
for several minutes at 1,000–
2,000 r/min while occasionally
revving it to 4,000–5,000 r/min.NOTE:
The engine is warm when it quickly
responds to the throttle.2. Check the engine idling speed
and, if necessary, adjust it to
specification by turning the throt-
tle stop screw.
EAU00629
Adjusting the carburetorThe carburetor is an important part of
the engine and requires very sophisti-
cated adjustment. Therefore, most
carburetor adjustments should be left
to a Yamaha dealer, who has the
necessary professional knowledge
and experience. The adjustment
described in the following section,
however, may be serviced by the
owner as part of routine mainte-
nance.
EC000094
cCThe carburetor has been set and
extensively tested at the Yamaha
factory. Changing these settings
without sufficient technical knowl-
edge may result in poor perfor-
mance of or damage to the engine.
Recommended oil:
2-stroke engine oil
3MB-9-E8 6/13/01 10:55 AM Page 54

6-28
PERIODIC MAINTENANCE AND MINOR REPAIR
6
NOTE:
Make sure that both adjusting plates
are in the same position for proper
wheel alignment.
EC000096
cCImproper drive chain slack will
overload the engine as well as
other vital parts of the motorcycle
and can lead to chain slippage or
breakage. To prevent this from
occurring, keep the drive chain
slack within the specified limits.3. Tighten the axle nut to the speci-
fied torque.2. Wipe the drive chain dry.
3. Thoroughly lubricate the drive
chain with a special O-ring chain
lubricant.
ECA00052
cCDo not use engine oil or any other
lubricants for the drive chain, as
they may contain substances that
could damage the O-rings.
EAU03006
Lubricating the drive chainThe drive chain must be cleaned and
lubricated at the intervals specified in
the periodic maintenance and lubrica-
tion chart, otherwise it will quickly
wear out, especially when riding in
dusty or wet areas. Service the drive
chain as follows.
EC000097
cCThe drive chain must be lubricated
after washing the motorcycle or
riding in the rain.1. Clean the drive chain with
kerosene and a small soft brush.
ECA00053
cCTo prevent damaging the O-rings,
do not clean the drive chain with
steam cleaners, high-pressure
washers or inappropriate solvents.
Tightening torque:
Axle nut:
90 Nm (9.0 m0kgf)
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6-39
PERIODIC MAINTENANCE AND MINOR REPAIR
6
EAU00898
Front wheelTo remove the front wheel
EW000122
w8It is advisable to have a
Yamaha dealer service the
wheel.
8Securely support the motorcy-
cle so that there is no danger
of it falling over.1. Remove the brake disc cover by
removing the screws.
122
1. Disc cover
2. Screw (×2)
To service the rear wheel
Raise the rear wheel off the ground
by using a motorcycle stand or, if a
motorcycle stand is not available, by
placing a jack either under each side
of the frame in front of the rear wheel
or under each side of the swingarm.
EAU01579
Supporting the motorcycleSince this model is not equipped with
a centerstand, follow these precau-
tions when removing the front and
rear wheel or performing other main-
tenance requiring the motorcycle to
stand upright. Check that the motor-
cycle is in a stable and level position
before starting any maintenance. A
strong wooden box can be placed
under the engine for added stability.
To service the front wheel
1. Stabilize the rear of the motorcy-
cle by using a motorcycle stand
or, if an additional motorcycle
stand is not available, by placing
a jack under the frame in front of
the rear wheel.
2. Raise the front wheel off the
ground by using a motorcycle
stand.
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6-42
PERIODIC MAINTENANCE AND MINOR REPAIR
6
ECA00048
cCDo not apply the brake after the
wheel has been removed together
with the brake disc, otherwise the
brake pads will be forced shut.
EAU04237
Rear wheelWheel (rear)
EW000122
w8It is advisable to have a
Yamaha dealer service the
wheel.
8Securely support the motorcy-
cle so that there is no danger
of it falling over.1. Loosen the axle nut.
2. Lift the rear wheel off the ground
according to the procedure on
page 6-39.
3. Remove the swingarm end bolts.
2
2
1
1. Axle nut
2. Swingarm end bolt (×2)
4. Turn the drive chain adjusting
plate on each side of the
swingarm fully in direction a.
5. Push the wheel forward, and
then remove the drive chain from
the rear sprocket.NOTE:
The drive chain does not need to be
disassembled in order to remove and
install the rear wheel.6. Pull the wheel axle out from the
left-hand side, and then remove
the wheel by pulling it back.
1
a
1. Chain adjusting plate
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6-43
PERIODIC MAINTENANCE AND MINOR REPAIR
6
EAU03087
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 charts
represent quick and easy procedures
for checking these vital systems your-
self. However, should your motorcy-
cle require any repair, take it to a
Yamaha dealer, whose skilled techni-
cians 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.
EAU01806
To install the rear wheel
1. Install the drive chain onto the
rear sprocket, and then insert the
wheel axle from the left side.NOTE:
Make sure that there is enough
space between the brake pads
before inserting the brake disc
between the pads.2. Install the swingarm end bolts,
and then lower the rear wheel so
that it is on the ground.
3. Adjust the drive chain slack.
(See page 6-27 for drive chain
slack adjustment procedures.)
4. Tighten the axle nut and
swingarm end bolts to the speci-
fied torques.
Tightening torques:
Axle nut:
90 Nm (9.0 m0kgf)
Swingarm end bolts:
3 Nm (0.3 m0kgf)
3MB-9-E8 6/13/01 10:55 AM Page 80