YAMAHA DT125R 2002 Repair Manual

6-23
PERIODIC MAINTENANCE AND MINOR REPAIR
6
EAU00712
Adjusting the brake pedal
positionThe top of the brake pedal should be
positioned approximately 15 mm
below the top of the footrest as
shown. Periodically check the brake
pedal position and, if necessary,
have a Yamaha dealer adjust it.
a
1
1. Footrest
a. Brake pedal position
EW000099
w8After adjusting the brake lever
free play, check the free play
and make sure that the brake
is working properly.
8A soft or spongy feeling in the
brake lever can indicate the
presence of air in the
hydraulic system. If there is air
in the hydraulic system, have
a Yamaha dealer bleed the
system before operating the
motorcycle. Air in the
hydraulic system will diminish
the braking performance,
which may result in loss of
control and an accident.
EAU00696
Adjusting the brake lever
free playThe brake lever free play should
measure 2–5 mm as shown.
Periodically check the brake lever
free play and, if necessary, adjust it
as follows.
1. Loosen the locknut at the brake
lever.
2. To increase the brake lever free
play, turn the adjusting bolt in
direction a. To decrease the
brake lever free play, turn the
adjusting bolt in direction b.
3. Tighten the locknut.
2
1b
a
c
1. Locknut
2. Adjusting bolt
c. Free play
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6-24
PERIODIC MAINTENANCE AND MINOR REPAIR
6
EW000109
wA soft or spongy feeling in the
brake pedal can indicate the pres-
ence of air in the hydraulic system.
If there is air in the hydraulic sys-
tem, have a Yamaha dealer bleed
the system before operating the
motorcycle. Air in the hydraulic
system will diminish the braking
performance, which may result in
loss of control and an accident.
EAU00721
Checking the front and rear
brake padsThe front and rear brake pads must
be checked for wear at the intervals
specified in the periodic maintenance
and lubrication chart.
EAU00713
Adjusting the rear brake light
switchThe rear brake light switch, which is
activated by the brake pedal, is prop-
erly adjusted when the brake light
comes on just before braking takes
effect. If necessary, adjust the brake
light switch as follows.
Turn the adjusting nut while holding
the rear brake light switch in place.
To make the brake light come on ear-
lier, turn the adjusting nut in direction
a. To make the brake light come on
later, turn the adjusting nut in direc-
tion b.
b
a 1
2
1. Brake light switch
2. Adjusting nut
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6-25
PERIODIC MAINTENANCE AND MINOR REPAIR
6
EAU00724
Front brake pads
Each front brake pad is provided with
a wear indicator, which allows you to
check the brake pad wear without
having to disassemble the brake. To
check the brake pad wear, check the
position of the wear indicator while
applying the brake. If a brake pad
has worn to the point that the wear
indicator almost touches the brake
disc, have a Yamaha dealer replace
the brake pads as a set.
1
1. Wear indicator
EAU03776
Checking the brake fluid
levelInsufficient brake fluid may allow air
to enter the brake system, possibly
causing it to become ineffective.
Before riding, check that the brake
fluid is above the minimum level mark
and replenish if necessary. A low
brake fluid level may indicate worn
brake pads and/or brake system
leakage. If the brake level is low, be
sure to check the brake pads for
wear and the brake system for leak-
age.
1
1. Minimum level mark
EAU00728
Rear brake pads
Each rear brake pad is provided with
a wear indicator, which allows you to
check the brake pad wear without
having to disassemble the brake. To
check the brake pad wear, check the
position of the wear indicator while
applying the brake. If a brake pad
has worn to the point that the wear
indicator almost touches the brake
disc, have a Yamaha dealer replace
the brake pads as a set.
1
1. Wear indicator
FRONT
REAR
FRONT
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6-26
PERIODIC MAINTENANCE AND MINOR REPAIR
6 Observe these precautions:
8When checking the fluid level,
make sure that the top of the
brake fluid reservoir is level.
8Use only the recommended qual-
ity brake fluid, otherwise the rub-
ber seals may deteriorate, caus-
ing leakage and poor braking
performance.
1
1. Minimum level mark
EAU03976
Changing the brake fluidHave 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 master
cylinders and calipers as well as the
brake hoses replaced at the intervals
listed below or whenever they are
damaged or leaking.
8Oil seals: Replace every two
years.
8Brake hoses: Replace every four
years. 8Refill with the same type of brake
fluid. Mixing fluids may result in a
harmful chemical reaction and
lead to poor braking perfor-
mance.
8Be careful that water does not
enter the brake fluid reservoir
when refilling. Water will signifi-
cantly lower the boiling point of
the fluid and may result in vapor
lock.
8Brake fluid may deteriorate paint-
ed surfaces or plastic parts.
Always clean up spilled fluid
immediately.
8As the brake pads wear, it is nor-
mal for the brake fluid level to
gradually go down. However, if
the brake fluid level goes down
suddenly, have a Yamaha dealer
check the cause.
REARRecommended brake fluid:
DOT 4
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6-27
PERIODIC MAINTENANCE AND MINOR REPAIR
6
EAU00744
Drive chain slackThe 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.
a
a. Drive chain slack
EAU03594
To adjust the drive chain slack
1. Loosen the axle nut.
2. To tighten the drive chain, turn
the adjusting plate on each side
of the swingarm in direction a.
To loosen the drive chain, turn
the adjusting plate on each side
of the swingarm in direction b,
and then push the rear wheel for-
ward.
a b
2
1
1. Axle nut
2. Adjusting plate
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. Drive chain slack:
25–40 mm
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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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6-29
PERIODIC MAINTENANCE AND MINOR REPAIR
6
EAU04034
Checking and lubricating the
throttle grip and cableThe operation of the throttle grip
should be checked before each ride.
In addition, the cable should be lubri-
cated or replaced at the intervals
specified in the periodic maintenance
chart.
EAU02962
Checking and lubricating the
cablesThe operation of all control cables
and the condition of the cables
should be checked before each ride,
and the cables and cable ends
should be lubricated if necessary. If a
cable is damaged or does not move
smoothly, have a Yamaha dealer
check or replace it.
EW000112
wDamage to the outer sheath may
interfere with proper cable opera-
tion and will cause the inner cable
to rust. Replace a damaged cable
as soon as possible to prevent
unsafe conditions.
Recommended lubricant:
Engine oil
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6-30
PERIODIC MAINTENANCE AND MINOR REPAIR
6
EAU00774
Adjusting the Autolube
pumpThe Autolube pump is a vital and
sophisticated component of the
engine, which must be adjusted by a
Yamaha dealer at the intervals speci-
fied in the periodic maintenance and
lubrication chart.
EAU03370
Checking and lubricating the
brake and shift pedalsThe operation of the brake and shift
pedals should be checked before
each ride, and the pedal pivots
should be lubricated if necessary.
EAU03164
Checking and lubricating the
brake and clutch leversThe operation of the brake and clutch
levers should be checked before
each ride, and the lever pivots should
be lubricated if necessary.
Recommended lubricant:
Lithium-soap-based grease
(all-purpose grease)
Recommended lubricant:
Lithium-soap-based grease
(all-purpose grease)
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6-31
PERIODIC MAINTENANCE AND MINOR REPAIR
6
EAU02939
Checking the front forkThe condition and operation of the
front fork must be checked as follows
at the intervals specified in the peri-
odic maintenance and lubrication
chart.
To check the condition
EW000115
wSecurely support the motorcycle
so that there is no danger of it
falling over.Check the inner tubes for scratches,
damage and excessive oil leakage.To check the operation
1. Place the motorcycle on a level
surface and hold it in an upright
position.
2. While applying the front brake,
push down hard on the handle-
bars several times to check if the
front fork compresses and
rebounds smoothly.
EC000098
cCIf any damage is found or the front
fork does not operate smoothly,
have a Yamaha dealer check or
repair it.
EAU03165
Checking and lubricating the
sidestandThe operation of the sidestand
should be checked before each ride,
and the sidestand pivot and metal-to-
metal contact surfaces should be
lubricated if necessary.
EW000113
wIf the sidestand does not move up
and down smoothly, have a
Yamaha dealer check or repair it.
Recommended lubricant:
Lithium-soap-based grease
(all-purpose grease)
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6-32
PERIODIC MAINTENANCE AND MINOR REPAIR
6 2. Hold the lower ends of the front
fork legs and try to move them
forward and backward. If any
free play can be felt, have a
Yamaha dealer check or repair
the steering.
EAU01144
Checking the wheel bearingsThe front and rear wheel bearings
must be checked at the intervals
specified in the periodic maintenance
and lubrication chart. If there is play
in the wheel hub or if the wheel does
not turn smoothly, have a Yamaha
dealer check the wheel bearings.
EAU00794
Checking the steeringWorn or loose steering bearings may
cause danger. Therefore, the opera-
tion of the steering must be checked
as follows at the intervals specified in
the periodic maintenance and lubrica-
tion chart.
1. Place a stand under the engine
to raise the front wheel off the
ground.
EW000115
wSecurely support the motorcycle
so that there is no danger of it
falling over.
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