2002 YAMAHA YZ125LC oil

5-5
CHASFRONT WHEEL AND REAR WHEEL
EC595000
ASSEMBLY AND INSTALLATION
EC595101
Front wheel
1. Install:
9Bearing (left) 1
9Spacer 2
9Bearing (right) 3
9Oil seal 4
NOTE:
9Apply the lithium soap base grease on the
bearing and oil seal lip when installing.
9Use a socket that matches the outside diam-
eter of the race of the bearing.
9Left side of bearing shall be installed first.
9Install the oil seal with its manufacture’s
marks or numbers facing outward.
cC
Do not strike the inner race of the bearing.
Contact should be made only with the out-
er race.
2. Install:
9Brake disc 1
9Bolt (brake disc) 2
NOTE:
Tighten the bolts in stage, using a crisscross
pattern.
3. Install:
9Collar 1
NOTE:
9Apply the lithium soap base grease on the oil
seal lip.
9Install the collars with their projections afac-
ing the wheel.
4. Install:
9Wheel
NOTE:
Install the brake disc 1between the brake pads
2correctly.
12 Nm (1.2 m•kg, 8.7 ft•lb)
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5-7
CHASFRONT WHEEL AND REAR WHEEL
EC5251A0
Rear wheel
1. Install:
9Bearing (right) 1
9Circlip 2
9Spacer 3
9Bearing (left) 4
9Oil seal 5
NOTE:
9Apply the lithium soap base grease on the
bearing and oil seal lip when installing.
9Install the bearing with seal facing outward.
9Use a socket that matches the outside diam-
eter of the race of the bearing.
9Right side of bearing shall be installed first.
9Install the oil seal with its manufacture’s
marks or numbers facing outward.
cC
Do not strike the inner race of the bearing.
Contact should be made only with the out-
er race.
2. Install:
9Brake disc 1
9Bolt (brake disc) 2
NOTE:
Tighten the bolts in stage, using a crisscross
pattern.
9. Install:
9Hose cover 1
9Plain washer 2
9Bolt [hose cover (M8)] 3
9Bolt [hose cover (M6)] 4
16 Nm (1.6 m•kg, 11 ft•lb)
7 Nm (0.7 m•kg, 5.1 ft•lb)
14 Nm (1.4 m•kg, 1.0 ft•lb)
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5-8
CHASFRONT WHEEL AND REAR WHEEL
3. Install:
9Driven sprocket 1
9Bolt (driven sprocket) 2
9Plain washer (driven sprocket) 3
9Nut (driven sprocket) 4
NOTE:
Tighten the nuts in stage, using a crisscross pat-
tern.
4. Install:
9Collar 1
NOTE:
Apply the lithium soap base grease on the oil
seal lip.
5. Install:
9Wheel
NOTE:
Install the brake disc 1between the brake pads
2correctly.
6. Install:
9Drive chain 1
NOTE:
Push the wheel 2forward and install the drive
chain.
7. Install:
9Chain puller (left) 1
9Wheel axle 2
NOTE:
9Install the chain puller (left), and insert the
wheel axle from left side.
9Apply the lithium soap base grease on the
wheel axle.
42 Nm (4.2 m•kg, 30 ft•lb)
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5-25
CHASFRONT BRAKE AND REAR BRAKE
2. Install:
9Brake hose holder 1
9Screw (brake hose holder) 2
cC
After installing the brake hose holders,
make sure the brake hose does not contact
the spring (rear shock absorber). If it does,
correct its twist.
EC5A5600
Brake fluid
1. Fill:
9Brake fluid
Until the fluid level reaches “LOWER” level
line a.
w
9Use only the designated quality brake fluid:
otherwise, the rubber seals may deterio-
rate, causing leakage and poor brake per-
formance.
9Refill with the same type of brake fluid;
mixing fluids may result in a harmful chemi-
cal reaction and lead to poor performance.
9Be careful that water does not enter the
master cylinder when refilling. Water will
significantly lower the boiling point of the
fluid and may result in vapor lock.
cC
Brake fluid may erode painted surfaces or
plastic parts. Always clean up spilled fluid
immediately.
AFront
BRear
Recommended brake fluid:
DOT #4
2 Nm (0.2 m•kg, 1.4 ft•lb)
5NY-9-30-5A 5/23/01 9:01 PM Page 50

5-28
CHASFRONT FORK
Extent of removal Order Part name Q’ty Remarks
FRONT FORK DISASSEMBLY
1Cap bolt 1 Refer to “REMOVAL POINTS”.
2Fork spring 1 Drain the folk oil.
3Dust seal 1
4Stopper ring 1 Refer to “REMOVAL POINTS”.
5Inner tube 1
6Outer tube 1
7Piston metal 1
8Slide metal 1
9Plain washer 1
0Oil seal 1
qSpring guide 1
wBase valve 1 Use special tool.
eDamper rod 1 Refer to “REMOVAL POINTS”.
EC558000
FRONT FORK DISASSEMBLY
1
Extent of removal:1Oil seal removal2Damper rod removal
2






29 Nm (2.9 m•kg, 21 ft•lb)1 Nm (0.1 m•kg, 0.7 ft•lb)
30 Nm (3.0 m•kg, 22 ft•lb)
55 Nm (5.5 m•kg, 40 ft•lb)
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5-29
CHASFRONT FORK
EC556000
HANDLING NOTE
NOTE:
The front fork requires careful attention. So it is
recommended that the front fork be maintained
at the dealers.
cC
To prevent an accidental explosion of air,
the following instructions should be ob-
served:
9The front fork with a built-in piston rod
has a very sophisticated internal con-
struction and is particularly sensitive to
foreign material.
Use enough care not to allow any foreign
material to come in when the oil is re-
placed or when the front fork is disassem-
bled and reassembled.
9Before removing the cap bolts or front
forks, be sure to extract the air from the air
chamber completely.
EC553000
REMOVAL POINTSEC553151
Cap bolt
1. Remove:
9Cap bolt 1
From the outer tube.
NOTE:
Before removing the front fork from the machine,
loosen the cap bolt.
2. Remove:
9Cap bolt 1
NOTE:
9While compressing the fork spring, set the thin
type spanners 2between the spacer 3and
spring guide 4.
9Hold the locknut 5and remove the cap bolt.
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5-30
CHASFRONT FORK
EC553201
Inner tube
1. Remove:
9Dust seal 1
9Stopper ring 2
Using slotted-head screwdriver.
cC
Take care not to scratch the inner tube.
2. Remove:
9Inner tube 1
EC553311
Damper rod
1. Remove:
9Base valve 1
9Damper rod 2
NOTE:
Use a damper rod holder 3to lock the
damper rod.
EC554000
INSPECTIONEC554100
Damper rod
1. Inspect:
9Damper rod 1
Bend/DamageReplace damper rod.
cC
The front fork with a built-in piston rod has
a very sophisticated internal construction
and is particularly sensitive to foreign ma-
terial.
Use enough care not to allow any foreign
material to come in when the oil is re-
placed or when the front fork is disassem-
bled and reassembled.
Oil seal removal steps:
9Push in slowly athe inner tube just be-
fore it bottoms out and then pull it back
quickly b.
9Repeat this step until the inner tube can
be pulled out from the outer tube.
Damper rod holder:
YM-1423/90890-01423
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5-31
CHASFRONT FORK
EC554200
Base valve
1. Inspect:
9Valve assembly 1
Wear/DamageReplace.
9O-ring 2
DamageReplace.
EC554400
Fork spring
1. Measure:
9Fork spring free length a
Out of specificationReplace.
EC554502
Inner tube
1. Inspect:
9Inner tube surface a
Score marksRepair or replace.
Use #1,000 grit wet sandpaper.
Damaged oil lock pieceReplace.
9Inner tube bends
Out of specificationReplace.
Use the dial gauge 1.
NOTE:
The bending value is shown by one half of the
dial gauge reading.
w
Do not attempt to straighten a bent inner
tube as this may dangerously weaken the
tube.
EC554600
Outer tube
1. Inspect:
9Outer tube 1
Score marks/Wear/DamageReplace.
Standard
460 mm 455 mm
(18.1 in) (17.9 in)Fork spring free length:
Inner tube bending limit:
0.2 mm (0.008 in)
5NY-9-30-5B 5/23/01 9:05 PM Page 10