warning YAMAHA YZ250F 2007 Owner's Guide

5 - 23
CHASFRONT BRAKE AND REAR BRAKE
4. Install:
Copper washer 1
Brake hose 2
Union bolt 3
WARNING
Always use new copper washers.
CAUTION:
Install the brake hose so that its pipe por-
tion
a directs as shown and lightly
touches the projection
b on the brake
master cylinder.
T R..30 Nm (3.0 m · kg, 22 ft · lb)
Rear brake hose
1. Install:
Copper washer 1
Brake hose 2
Union bolt 3
WARNING
Always use new copper washers.
CAUTION:
Install the brake hose so that its pipe por-
tion
a directs as shown and lightly
touches the projection
b on the brake cali-
per.
T R..30 Nm (3.0 m · kg, 22 ft · lb)

5 - 24
CHASFRONT BRAKE AND REAR BRAKE
2. Install:
Brake hose holder 1
Screw (brake hose holder) 2
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:
Brake fluid
Until the fluid level reaches “LOWER”
level line a.
WARNING
Use only the designated quality brake
fluid:
otherwise, the rubber seals may deterio-
rate, causing leakage and poor brake per-
formance.
Refill with the same type of brake fluid;
mixing fluids may result in a harmful
chemical reaction and lead to poor perfor-
mance.
Be 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.
CAUTION:
Brake fluid may erode painted surfaces or
plastic parts. Always clean up spilled fluid
immediately.
È
Front
ÉRear
Recommended brake fluid:
DOT #4
T R..2 Nm (0.2 m · kg, 1.4 ft · lb)
È
É

5 - 26
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 no
danger 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 Refer to “SEAT, FUEL TANK AND SIDE
COVERS” section in the CHAPTER 4.
1 Protector 1
2 Pinch bolt (upper bracket) 2 Only loosening.
3 Damper assembly 1 Loosen when disassembling the front
fork.
Use special tool.
Refer to “REMOVAL POINTS”.
4 Pinch bolt (lower bracket) 2 Only loosening.
5 Front fork 1
1

5 - 32
CHAS
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.
Inner tube bending limit:
0.2 mm (0.008 in)
EC554600
Outer tube
1. Inspect:
Outer tube 1
Score marks/wear/damage → Replace.
Adjuster
1. Inspect:
Adjuster 1
O-ring 2
Wear/damage → Replace.
FRONT FORK

5 - 40
CHAS
30. Install:
Adjuster 1
To inner tube.
T R..55 Nm (5.5 m · kg, 40 ft · lb)
31. Fill:
Front fork oil 1
From outer tube top.
WARNING
Never fail to make the oil amount adjust-
ment between the maximum and minimum
amount and always adjust each front fork
to the same setting. Uneven adjustment
can cause poor handling and loss of stabil-
ity.
CAUTION:
Be sure to use recommended fork oil. If
other oils are used, they may have an
excessively adverse effect on the front
fork performance.
Never allow foreign materials to enter the
front fork.
Recommended oil:
Suspension oil “S1”
Standard oil amount:
340 cm
3 (12.0 Imp oz, 11.5 US oz)
Extent of adjustment:
300 ~ 380 cm
3
(10.6 ~ 13.4 Imp oz,
10.1 ~ 12.8 US oz)
32. Install:
Damper assembly 1
To outer tube.
NOTE:
Temporarily tighten the damper assembly.
FRONT FORK

5 - 44
CHAS
EC5B3000
REMOVAL POINTS
Brake master cylinder
1. Remove:
Brake master cylinder bracket 1
Brake master cylinder 2
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.
EC5B5000
ASSEMBLY AND INSTALLATION
Handlebar
1. Install:
Handlebar lower holder 1
Washer 2
Nut (handlebar lower holder) 3
NOTE:
Install the handlebar lower holder with its
side having the greater distance a from the
mounting bolt center facing forward.
Apply the lithium soap base grease on the
thread of the handlebar lower holder.
Installing the handlebar lower holder in the
reverse direction allows the front-to-rear off-
set amount of the handlebar position to be
changed.
Do not tighten the nut yet.
HANDLEBAR

5 - 47
CHASHANDLEBAR
7. 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.
8. 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)
9. Install:
•Grip cap cover 1
•Cover (throttle cable cap) 2
10. Install:
•Brake master cylinder 1
•Brake master cylinder bracket 2
•Bolt (brake master cylinder bracket) 3
NOTE:
•Install the bracket so that the arrow mark a
faces upward.
•First 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 - 49
CHAS
EC560000
STEERING
Extent of removal:
1 Lower bracket removal
2 Bearing removal
Extent of removal Order Part name Q’ty Remarks
STEERING REMOVAL
WARNING
Support the machine securely so
there is no danger of it falling over.
Refer to “SEAT, FUEL TANK AND SIDE
COVERS” section in the CHAPTER 4. Preparation for removal Hold the machine by placing the
suitable stand under the engine.
Number plate
Handlebar
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 Bearing race cover 1
7 Upper bearing 1
8 Lower bearing 1 Refer to “REMOVAL POINTS”.
9 Bearing race 2 Refer to “REMOVAL POINTS”.
2
1
STEERING

5 - 50
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.
CAUTION:
Take care not to damage the steering shaft
thread.
Bearing race
1. Remove:
•Bearing race 1
Remove the bearing race using long rod
2 and the hammer.
EC564000
INSPECTION
Steering stem
1. Inspect:
•Steering stem 1
Bend/damage → Replace.
STEERING

5 - 54
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 Refer to “FRONT BRAKE AND REAR
BRAKE” section.
Shift the brake pedal backward. Rear brake caliper
Bolt (brake pedal)
Drive chain
1 Drive chain support 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