2002 YAMAHA YZ250F warning

5 - 27
CHASFRONT FORK
EC550000
FRONT FORK
Extent of removal:1 Front fork removal
Extent of removal Order Part name Q’ty Remarks
Preparation for removalFRONT FORK REMOVAL
Hold the machine by placing the
suitable stand under the engine.
WARNING
Support the machine securely so there is nodanger of it falling over.
Front wheel Refer to “FRONT WHEEL AND REAR
WHEEL” section.
Front brake caliper Refer to “FRONT BRAKE AND REAR
BRAKE” section.
Number plate
Handlebar Refer to “HANDLEBAR” section.
1 Protector 1
2 Brake hose holder 2
3 Pinch bolt (upper bracket) 2 Only loosening.
4 Cap bolt 1Loosen when disassembling the front fork.
5 Pinch bolt (lower bracket) 2 Only loosening.
6 Front fork 1
1

5 - 31
CHAS

EC554200
Base valve
1. Inspect:

Valve assembly
1

Wear/damage
→
Replace.

O-ring
2

Damage
→
Replace.
EC554400
Fork spring
1. Measure:

Fork spring free length
a

Out of specification
→
Replace.
EC554502
Inner tube
1. Inspect:

Inner tube surface
a

Score marks
→
Repair or replace.
Use #1,000 grit wet sandpaper.
Damaged oil lock piece
→
Replace.

Inner tube bends
Out of specification
→
Replace.
Use the dial gauge
1
.
NOTE:

The bending value is shown by one half of the
dial gauge reading.
WARNING

Do not attempt to straighten a bent inner
tube as this may dangerously weaken the
tube.
EC554600
Outer tube
1. Inspect:

Outer tube
1

Score marks/wear/damage
→
Replace.
Fork spring free length:
460 mm (18.1 in)
: 455 mm (17.9 in)
Inner tube bending limit:
0.2 mm (0.008 in)
FRONT FORK

5 - 36
CHASFRONT FORK
19. Wait ten minutes until the air bubbles
have been removed from the front fork,
and the oil has dispense evenly in system
before setting recommended oil level.
NOTE:
Fill with the fork oil up to the top end of the
outer tube, or the fork oil will not spread over to
every part of the front forks, thus making it
impossible to obtain the correct level.
Be sure to fill with the fork oil up to the top of
the outer tube and bleed the front forks.
20. Measure:
Oil level (left and right) a
Out of specification → Adjust.
NOTE:
Be sure to install the spring guide 2 when
checking the oil level.
WARNING
Never fail to make the oil level adjustment
between the maximum and minimum level
and always adjust each front fork to the
same setting. Uneven adjustment can
cause poor handling and loss of stability.
Standard oil level:
140 mm (5.51 in)
Extent of adjustment:
80 ~ 150 mm (3.15 ~ 5.91 in)
From top of outer tube with
inner tube and damper rod 1
fully compressed without
spring.

5 - 41
CHAS
EC5B3000
REMOVAL POINTS
Brake master cylinder
1. Remove:
Brake master cylinder bracket 1
Brake master cylinder 2
ACHTUNG:CAUTION:
Do not let the brake master cylinder hang
on the brake hose.
Keep the brake master cylinder cap side
horizontal to prevent air from coming in.
EC5B3200
Grip
1. Remove:
Grip 1
NOTE:
Blow in air between the handlebar or tube
guide and the grip. Then remove the grip
which has become loose.
EC5B4000
INSPECTION
EC5B4100
Handlebar
1. Inspect:
Handlebar 1
Bends/cracks/damage → Replace.
WARNING
Do not attempt to straighten a bent handle-
bar as this may dangerously weaken the
handlebar.
HANDLEBAR

5 - 43
CHASHANDLEBAR
4. Install:
Collar 1
Grip cap cover 2
Throttle grip 3
NOTE:
Apply the lithium soap base grease on the
throttle grip sliding surface.
5. Install:
Throttle cables 1
To tube guide 2.
NOTE:
Apply the lithium soap base grease on the
throttle cable end and tube guide cable wind-
ing portion.
6. Install:
Throttle cable cap 1
Screw (throttle cable cap) 2
WARNING
After tightening the screws, check that the
throttle grip 3 moves smoothly. If it does
not, retighten the bolts for adjustment.
T R..4 Nm (0.4 m · kg, 2.9 ft · lb)
7. Install:
Grip cap cover 1
Cover (throttle cable cap) 2

5 - 46
CHAS
EC560000
STEERING
Extent of removal:1 Lower bracket removal2 Bearing removal
Extent of removal Order Part name Q’ty Remarks
STEERING REMOVAL
WARNING
Support the machine securely so there is nodanger of it falling over.Preparation for removal Hold the machine by placing the
suitable stand under the engine.
Number plate
Handlebar
Cable guide
Front fenderRefer to “HANDLEBAR” section.
1 Steering stem nut 1
2 Front fork 2 Refer to “FRONT FORK” section.
3 Upper bracket 1
4 Steering ring nut 1 Use special tool.
Refer to “REMOVAL POINTS”.
5 Lower bracket 1
6 Ball race cover 1
7 Upper bearing 1
8 Lower bearing 1 Refer to “REMOVAL POINTS”.
9Ball race
2Refer to “REMOVAL POINTS”.
2
1
STEERING

5 - 47
CHAS
EC563000
REMOVAL POINTS
Steering ring nut
1. Remove:
Steering ring nut 1
Use the steering nut wrench 2.
WARNING
Support the steering stem so that it may
not fall down.
Steering nut wrench:
YU-33975/90890-01403
Lower bearing
1. Remove:
Lower bearing 1
Use the floor chisel 2.
ACHTUNG:CAUTION:
Take care not to damage the steering shaft
thread.
EC563400
Ball race
1. Remove:
Ball race 1
Remove the ball race using long rod 2
and the hammer.
EC564000
INSPECTION
Steering stem
1. Inspect:
Steering stem 1
Bend/damage → Replace.
STEERING

5 - 51
CHASSWINGARM
EC570000
SWINGARM
Extent of removal:1 Swingarm removal
Extent of removal Order Part name Q’ty Remarks
SWINGARM REMOVAL
WARNING
Support the machine securely so there is no
danger of it falling over.
Preparation for removal Hold the machine by placing the
suitable stand under the engine.
Brake hose holder
Rear brake caliper
Bolt (brake pedal)
Drive chainRefer to “FRONT BRAKE AND REAR
BRAKE” section.
Shift the brake pedal backward.
1 Drive chain case 1
2 Lower chain tensioner 1
3 Bolt (rear shock absorber-relay
arm)1 Hold the swingarm.
4 Bolt (connecting rod) 1
5 Pivot shaft 1
6 Swingarm 1
1