warning YAMAHA YZ250F 2001 Owner's Guide

5 - 24
CHASFRONT BRAKE AND REAR BRAKE
4. Install:
lCopper washer 1
lBrake hose 2
lUnion bolt 3
WARNING
Always use new copper washers.
ACHTUNG:CAUTION:
Install the brake hose so that its pipe por-
tion a directs as show and lightly touches
the projection b on the brake master cylin-
der.
T R..30 Nm (3.0 m · kg, 22 ft · lb)
Rear brake hose
1. Install:
lCopper washer 1
lBrake hose 2
lCopper washer 3
lUnion bolt 4
WARNING
Always use new copper washers.
ACHTUNG:CAUTION:
When installing the brake hose, first align
the tooth a on the copper washer 1 with
the projection b on the brake master cylin-
der. Then, align the pipe portion c on the
end of the brake hose with the tooth d on
the copper washer 1 and tighten the union
bolt.
T R..30 Nm (3.0 m · kg, 22 ft · lb)

5 - 25
CHASFRONT BRAKE AND REAR BRAKE
2. Install:
lBrake hose holder 1
lScrew (brake hose holder) 2
ACHTUNG:CAUTION:
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.
Brake fluid
1. Fill:
lBrake fluid
Until the fluid level reaches “LOWER”
level line a.
WARNING
lUse only the designated quality brake
fluid:
otherwise, the rubber seals may deterio-
rate, causing leakage and poor brake per-
formance.
lRefill with the same type of brake fluid;
mixing fluids may result in a harmful chem-
ical reaction and lead to poor performance.
lBe 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.
ACHTUNG:CAUTION:
Brake fluid may erode painted surfaces or
plastic parts. Always clean up spilled fluid
immediately.
Front
õRear
Recommended brake fluid:
DOT #4
T R..4 Nm (0.4 m · kg, 2.9 ft · lb)

õ

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:
lValve assembly 1
Wear/damage ® Replace.
lO-ring 2
Damage ® Replace.
EC554400
Fork spring
1. Measure:
lFork spring free length a
Out of specification ® Replace.
EC554502
Inner tube
1. Inspect:
lInner tube surface a
Score marks ® Repair or replace.
Use #1,000 grit wet sandpaper.
Damaged oil lock piece ® Replace.
lInner 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:
lOuter 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:
lOil 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:
lBrake master cylinder bracket 1
lBrake master cylinder 2
ACHTUNG:CAUTION:
lDo not let the brake master cylinder hang
on the brake hose.
lKeep the brake master cylinder cap side
horizontal to prevent air from coming in.
EC5B3200
Grip
1. Remove:
lGrip 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:
lHandlebar 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:
lCollar 1
lThrottle cables 2
To tube guide 3.
NOTE:
Apply the lithium soap base grease on the
throttle cable end and tube guide cable wind-
ing portion.
5. Install:
lThrottle cable cap 1
lScrew (throttle cable cap) 2
lCover (throttle cable cap) 3
WARNING
After tightening the screws, check that the
throttle grip 4 moves smoothly. If it does
not, retighten the bolts for adjustment.
T R..4 Nm (0.4 m · kg, 2.9 ft · lb)
6. Install:
lBrake master cylinder 1
lBrake master cylinder bracket 2
lBolt (brake master cylinder bracket) 3
NOTE:
lInstall the bracket so that the arrow mark a
faces upward.
lFirst tighten the bolt on the upper side of the
brake master cylinder bracket, and then
tighten the bolt on the lower side.
T R..9 Nm (0.9 m · kg, 6.5 ft · lb)

5 - 45
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 - 46
CHAS
EC563000
REMOVAL POINTS
Steering ring nut
1. Remove:
lSteering ring nut 1
Use the steering nut wrench 2.
WARNING
Support the steering shaft so that it may
not fall down.
Steering nut wrench:
YU-33975/90890-01403
Lower bearing
1. Remove:
lLower bearing 1
Use the floor chisel 2.
ACHTUNG:CAUTION:
Take care not to damage the steering shaft
thread.
EC563400
Ball race
1. Remove:
lBall race 1
Remove the ball race using long rod 2
and the hammer.
EC564000
INSPECTION
Steering stem
1. Inspect:
lSteering stem 1
Bend/damage ® Replace.
STEERING

5 - 50
CHASSWINGARM
EC570000
SWINGARM
Extent of removal:1 Swingarm 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.
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