warning YAMAHA YZ250F 2001 User Guide

3 - 26
INSP
ADJ
FRONT BRAKE ADJUSTMENT
3. Install:
lProtector (rear brake)
lDiaphragm
lReservoir cap
NOTE:
If bleeding is difficult, it may be necessary to
let the brake fluid system stabilize for a few
hours. Repeat the bleeding procedure when
the tiny bubbles in the system have disap-
peared.
j. Add brake fluid to the level line on the
reservoir.
WARNING
Check the operation of the brake after
bleeding the brake system.
EC362040
FRONT BRAKE ADJUSTMENT
1. Check:
lBrake lever position a
Brake lever position a:
Standard position Extent of adjustment
95 mm (3.74 in)76 ~ 97 mm
(2.99 ~ 3.82 in)
2. Adjust:
lBrake lever position
Brake lever position adjustment steps:
lLoosen the locknut 1.
lTurn the adjusting bolt 2 until the lever
position a is within specified position.
lTighten the locknut.
T R..
Locknut:
5 Nm (0.5 m • kg, 3.6 ft • lb)
CAUTION:
Be sure to tighten the locknut, as it will
cause poor brake performance.
2
1

3 - 27
INSP
ADJREAR BRAKE ADJUSTMENT/
FRONT BRAKE PAD INSPECTION AND REPLACEMENT
EC364002
REAR BRAKE ADJUSTMENT
1. Check:
lBrake pedal height a
Out of specification ® Adjust.
Brake pedal height a:
5 mm (0.20 in)
2. Adjust:
lBrake pedal height
Pedal height adjustment steps:
lLoosen the locknut 1.
lTurn the adjusting nut 2 until the pedal
height a is within specified height.
lTighten the locknut.
WARNING
lAdjust the pedal height between the
maximum and the minimum õ as
shown. (In this adjustment the bolt 3
end b should protrude out of the lower
adjusting nut 4 but not be less than
2 mm (0.08 in) c away from the brake
pedal 5).
lAfter the pedal height adjustment, make
sure that the rear brake does not drag.

õ
FRONT BRAKE PAD INSPECTION AND
REPLACEMENT
1. Inspect:
lBrake pad thickness a
Out of specification ® Replace as a
set.
2. Replace:
lBrake pad
Brake pad thickness:
4.4 mm (0.17 in)
: 1.0 mm (0.04 in)
Brake pad replacement steps:
lRemove the pad pin plug 1.

3 - 31
INSP
ADJREAR BRAKE PAD INSULATOR INSPECTION/
BRAKE FLUID LEVEL INSPECTION
3. Inspect:
lBrake fluid level
Refer to “BRAKE FLUID LEVEL
INSPECTION” section.
4. Check:
lBrake pedal operation
A softy or spongy feeling ® Bleed
brake system.
Refer to “BRAKE SYSTEM AIR
BLEEDING” section.
EC36b000
REAR BRAKE PAD INSULATOR
INSPECTION
1. Remove:
lBrake pad
Refer to “REAR BRAKE PAD INSPEC-
TION AND REPLACEMENT” section.
2. Inspect:
lRear brake pad insulator 1
Damage ® Replace.
BRAKE FLUID LEVEL INSPECTION
1. Place the brake master cylinder (reser-
voir tank) so that its top is in a horizontal
position.
2. Inspect:
lBrake fluid level
Fluid at lower level ® Fill up.
aLower level
Front
õRear
WARNING
lUse only designated quality brake fluid to
avoid poor brake performance.
lRefill with same type and brand of brake
fluid; mixing fluids could result in poor
brake performance.
lBe sure that water or other contaminants
do not enter master cylinder when refill-
ing.
lClean up spilled fluid immediately to
avoid erosion of painted surfaces or plas-
tic parts.
Recommended brake fluid:
DOT #4

õ

3 - 36
INSP
ADJFRONT FORK COMPRESSION DAMPING FORCE
ADJUSTMENT
CAUTION:
Do not force the adjuster past the minimum
or maximum extent of adjustment. The
adjuster may be damaged.
WARNING
Always adjust each front fork to the same
setting. Uneven adjustment can cause poor
handling and loss of stability.
EC36J001
FRONT FORK COMPRESSION DAMPING
FORCE ADJUSTMENT
1. Remove:
lRubber cap
2. Adjust:
lCompression damping force
By turning the adjuster 1.
Stiffer a ® Increase the compression
damping force. (Turn the adjuster 1
in.)
Softer b ® Decrease the compression
damping force. (Turn the adjuster 1
out.)
Extent of adjustment
Maximum Minimum
Fully turned in
position20 clicks out
(from maximum
position)

3 - 37
INSP
ADJ
REAR SHOCK ABSORBER INSPECTION
lSTANDARD POSITION:
This is the position which is back by the spe-
cific number of clicks from the fully turned-in
position.
* For EUROPE
CAUTION:
Do not force the adjuster past the minimum
or maximum extent of adjustment. The
adjuster may be damaged.
WARNING
Always adjust each front fork to the same
setting. Uneven adjustment can cause poor
handling and loss of stability.
3. Install:
lRubber cap
T R..
Standard position:
14 clicks out
*10 clicks out
EC36K000
REAR SHOCK ABSORBER INSPECTION
1. Inspect:
lSwingarm smooth action
Abnormal noise/unsmooth action ®
Grease the pivoting points or repair the
pivoting points.
Damage/oil leakage ® Replace.

3 - 44
INSP
ADJ
STEERING HEAD INSPECTION AND ADJUSTMENT
lTighten the steering ring nut 3 using
steering nut wrench 4.
NOTE:
Set the torque wrench to the steering nut
wrench so that they form a right angle.
Steering nut wrench:
YU-33975/90890-01403
T R..
Steering ring nut (initial tighten-
ing):
38 Nm (3.8 m • kg, 27 ft • lb)
lLoosen the steering ring nut one turn.
lRetighten the steering ring nut using the
steering nut wrench.
WARNING
Avoid over-tightening.
T R..
Steering ring nut (final tighten-
ing):
7 Nm (0.7 m • kg, 5.1 ft • lb)
lCheck the steering stem by turning it lock
to lock. If there is any binding, remove the
steering stem assembly and inspect the
steering bearings.
lInstall the upper bracket 5, steering stem
nut 6, handlebar 7, handlebar holder 8
and number plate 9.
NOTE:
lThe upper handlebar holder should be
installed with the punched mark a for-
ward.
lInsert the end of fuel breather hose 0 into
the hole of the number plate.
CAUTION:
First tighten the bolts on the front side of
the handlebar holder, and then tighten
the bolts on the rear side.
T R..
Steering shaft nut:
145 Nm (14.5 m • kg, 105 ft • lb)
Handlebar upper holder:
28 Nm (2.8 m • kg, 20 ft • lb)
Pinch bolt (handle crown):
23 Nm (2.3 m • kg, 17 ft • lb)
Number plate:
7 Nm (0.7 m • kg, 5.1 ft • lb)

4 - 5
ENG

RADIATOR
EC456000
HANDLING NOTE
WARNING

Do not remove the radiator cap when the
engine and radiator are hot. Scalding hot
fluid and steam may be blown out under
pressure, which could cause serious
injury.
When the engine has cooled, open the radi-
ator cap by the following procedure:
Place a thick rag, like a towel, over the radi-
ator cap, slowly rotate the cap counter-
clockwise to the detent. This procedure
allows any residual pressure to escape.
When the hissing sound has stopped,
press down on the cap while turning coun-
terclockwise and remove it.
EC454000
INSPECTION
EC444100
Radiator
1. Inspect:
l
Radiator core
1

Obstruction
®
Blow out with com-
pressed air through rear of the radiator.
Bent fin
®
Repair/replace.
EC455000
ASSEMBLY AND INSTALLATION
Radiator
1. Install:
l
O-ring
1
l
Radiator pipe
2

l
Bolt (radiator pipe)
3

NOTE:

Apply the lithium soap base grease on the O-
ring.
2. Install:
l
Radiator breather hose
1
lRadiator hose 4 (longer) 2
lRadiator hose 2 (shorter) 3
To left radiator 4.
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)

4 - 81
ENGENGINE REMOVAL
EC4M0000
ENGINE REMOVAL
Extent of removal Order Part name Q’ty Remarks
ENGINE REMOVAL
Preparation for removal Hold the machine by placing the
suitable stand under the frame.
WARNING
Support the machine securely so there is nodanger of it falling over.
Seat and fuel tank Refer to “SEAT, FUEL TANK AND SIDE
COVERS” section.
Carburetor Refer to “CARBURETOR” section.
Exhaust pipe and silencer Refer to “EXHAUST PIPE AND
SILENCER” section.
Clutch cable Disconnect at engine side.
Decompression cable and guide Disconnect at engine side.
Radiator Refer to “RADIATOR” section.
Shift pedal Refer to “KICK SHAFT AND SHIFT
SHAFT” section.
Cylinder head breather hose and
oil tank breather hoseRefer to “CAMSHAFTS” section.
Drain the engine oil Refer to “ENGINE OIL REPLACEMENT”
section in the CHAPTER 3.

5 - 1
CHAS

EC500000
CHASSIS
EC590000
FRONT WHEEL AND REAR WHEEL
EC598000
FRONT WHEEL
FRONT WHEEL AND REAR WHEEL
Extent of removal:
1
Front wheel removal
2
Wheel bearing removal
3
Brake disc removal
Extent of removal Order Part name Q’ty Remarks
Preparation for removal
FRONT WHEEL 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.
1 Brake hose cover 1
2 Bolt (brake hose holder) 2 Only loosening.
3 Bolt (axle holder) 4 Only loosening.
4 Nut (front wheel axle) 1
5 Front wheel axle 1
6 Front wheel 1
7 Collar 2
8 Oil seal 2
9 Bearing 2 Refer to “REMOVAL POINTS”.
10Brake disc
1
2
31
3





5

5 - 2
CHAS

EC598100
REAR WHEEL
Extent of removal:
1
Rear wheel removal
2
Wheel bearing removal
3
Brake disc removal
Extent of removal Order Part name Q’ty Remarks
Preparation for removal
REAR WHEEL 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.
1 Nut (rear wheel axle) 1
2 Rear wheel axle 1
3 Drive chain puller 2
4 Rear wheel 1 Refer to “REMOVAL POINTS”.
5 Collar 2
6 Rear wheel sprocket 1
7 Oil seal 2
8 Circlip 1
9 Bearing 2 Refer to “REMOVAL POINTS”.
10Brake disc
1
2
31
3

FRONT WHEEL AND REAR WHEEL