wheel YAMAHA YZ250F 2001 Manuale duso (in Italian)

SPEC
2 - 15
MAINTENANCE SPECIFICATIONS
NOTE:
- marked portion shall be checked for torque tightening after break-in or before each race.Part to be tightened Thread size Q’tyTightening torque
Nm m·kg ft·lb
Nipple (spoke) — 72 3 0.3 2.2
Rear wheel sprocket M8 ´ 1.25 6 42 4.2 30
Rear brake disc cover M6 ´ 1.0 2 7 0.7 5.1
Rear brake caliper protector M6 ´ 1.0 2 7 0.7 5.1
Engine mounting:
Engine and engine bracket (front) M10 ´ 1.25 1 69 6.9 50
Engine and frame (lower) M10 ´ 1.25 1 69 6.9 50
Engine bracket and frame M8 ´ 1.25 6 34 3.4 24
Engine and engine bracket (upper) M10 ´ 1.25 1 55 5.5 40
Lower engine guard M6 ´ 1.0 3 10 1.0 7.2
Right engine guard M8 ´ 1.25 2 10 1.0 7.2
Pivot shaft and nut M16 ´ 1.5 1 85 8.5 61
Relay arm and swingarm M14 ´ 1.5 1 80 8.0 58
Relay arm and connecting rod M14 ´ 1.5 1 80 8.0 58
Connecting rod and frame M14 ´ 1.5 1 80 8.0 58
Rear shock absorber and frame M10 ´ 1.25 1 56 5.6 40
Rear shock absorber and relay arm M10 ´ 1.25 1 53 5.3 38
Rear frame M8 ´ 1.25 3 29 2.9 21
Swingarm and brake hose holder M5 ´ — 4 4 0.4 2.9
Drive chain tensioner M8 ´ 1.25 2 19 1.9 13
Drive chain case M6 ´ 1.0 3 7 0.7 5.1
Seal guard and swingarm M5 ´ 0.8 4 6 0.6 4.3
Fuel tank M6 ´ 1.0 2 10 1.0 7.2
Fuel cock M6 ´ 1.0 2 7 0.7 5.1
Seat set bracket and fuel tank M6 ´ 1.0 1 7 0.7 5.1
Hooking screw (fitting band) and fuel tank M6 ´ 1.0 1 7 0.7 5.1
Radiator cover M6 ´ 1.0 6 4 0.4 2.9
Front fender M6 ´ 1.0 4 7 0.7 5.1
Rear fender M6 ´ 1.0 4 7 0.7 5.1
Side cover M6 ´ 1.0 2 7 0.7 5.1
Seat M8 ´ 1.25 2 23 2.3 17
Number plate M6 ´ 1.0 1 7 0.7 5.1

3 - 3
INSP
ADJ

MAINTENANCE INTERVALS
FRONT FORK OIL SEAL AND DUST
SEAL
Clean and lube
c

c
Lithium base grease
REAR SHOCK ABSORBER
Inspect and adjust
Lube
Retighten
c

c

c

c

c

c Molybdenum disulfide
grease
CHAIN GUARD AND ROLLERS
Inspect
c c
SWINGARM
Inspect and retighten
c c
RELAY ARM, CONNECTING ROD
Inspect and lube
c c Molybdenum disulfide
grease
STEERING HEAD
Inspect free play and retighten
Clean and lube
Replace bearing
c c
c
c Lithium base grease
TIRE, WHEELS
Inspect air pressure, wheel run-out,
tire wear and spoke looseness
Retighten sprocket bolt
Inspect bearings
Replace bearings
Lubricate
c
c
c
c
c
c
c
Lithium base grease
THROTTLE, CONTROL CABLE
Check routing and connection
Lubricate
c
c
c
c Yamaha cable lube or
SAE 10W-30 motor oil ItemAfter
break-inEvery
race
Every
third
(or
500 km)Every
fifth
(or
1,000 km)As re-
quiredRemarks

3 - 4
INSP
ADJ
PRE-OPERATION INSPECTION AND MAINTENANCE
EC320000
PRE-OPERATION INSPECTION AND MAINTENANCE
Before riding for break-in operation, practice or a race, make sure the machine is in good operating
condition.
Before using this machine, check the following points.
GENERAL INSPECTION AND MAINTENANCE
Item Routine Page
CoolantCheck that coolant is filled up to the radiator cap.
Check the cooling system for leakage.P.3-5 ~ 9
FuelCheck that a fresh gasoline is filled in the fuel tank. Check the
fuel line for leakage.P.1-13
Engine oilCheck that the oil level is correct. Check the crankcase and
frame oil line for leakage.P.3-13 ~ 17
Gear shifter and clutchCheck that gears can be shifted correctly in order and that the
clutch operates smoothly.P.3-9
Throttle grip/HousingCheck that the throttle grip operation and free play are correctly
adjusted. Lubricate the throttle grip and housing, if necessary.P.3-10 ~ 11
Brakes Check the play of front brake and effect of front and rear brake. P.3-25 ~ 31
Drive chainCheck drive chain slack and alignment. Check that the drive
chain is lubricated properly.P.3-32 ~ 34
WheelsCheck for excessive wear and tire pressure. Check for loose
spokes and have no excessive play.P.3-42 ~ 43
SteeringCheck that the handlebar can be turned smoothly and have no
excessive play.P.3-43 ~ 44
Front forks and rear shock
absorberCheck that they operate smoothly and there is no oil leakage. P.3-34 ~ 41
Cables (wires)Check that the clutch and throttle cables move smoothly. Check
that they are not caught when the handlebars are turned or
when the front forks travel up and down.—
Exhaust pipeCheck that the exhaust pipe is tightly mounted and has no
cracks.P.4-2
Rear wheel sprocket Check that the rear wheel sprocket tightening bolt is not loose. P.3-32
Lubrication Check for smooth operation. Lubricate if necessary. P.3-45
Bolts and nuts Check the chassis and engine for loose bolts and nuts. P.1-18
Lead connectorsCheck that the CDI magneto, CDI unit, and ignition coil are con-
nected tightly.P.1-6
SettingsIs the machine set suitably for the condition of the racing course
and weather or by taking into account the results of test runs
before racing? Are inspection and maintenance completely
done?P.7-1 ~ 22

3 - 29
INSP
ADJ
REAR BRAKE PAD INSPECTION AND REPLACEMENT
3. Inspect:
lBrake fluid level
Refer to “BRAKE FLUID LEVEL
INSPECTION” section.
lInstall the pad pin plug B.
T R..
Pad pin plug:
3 Nm (0.3 m • kg, 2.2 ft • lb)
4. Check:
lBrake lever operation
A softy or spongy feeling ® Bleed
brake system.
Refer to “BRAKE SYSTEM AIR
BLEEDING” section.
REAR 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:
6.4 mm (0.25 in)
: 1.0 mm (0.04 in)
Brake pad replacement steps:
lRemove the protector 1 and pad pin plug
2.
lLoosen the pad pin 3.
lRemove the rear wheel 4 and brake cali-
per 5.
Refer to “FRONT WHEEL AND REAR
WHEEL” section in the CHAPTER 5.

3 - 30
INSP
ADJ
REAR BRAKE PAD INSPECTION AND REPLACEMENT
lRemove the pad pin 6 and brake pads 7.
lConnect the transparent hose 8 to the
bleed screw 9 and place the suitable con-
tainer under its end.
lLoosen the bleed screw and push the
brake caliper piston in.
CAUTION:
Do not reuse the drained brake fluid.
lTighten the bleed screw.
T R..
Bleed screw:
6 Nm (0.6 m • kg, 4.3 ft • lb)
lInstall the brake pad 0 and pad pin A.
NOTE:
lInstall the brake pads with their projec-
tions a into the brake caliper recesses b.
lTemporarily tighten the pad pin at this
point.
lInstall the brake caliper B and rear wheel
C.
Refer to “FRONT WHEEL AND REAR
WHEEL” section in the CHAPTER 5.
lTighten the pad pin D.
T R..
Pad pin:
18 Nm (1.8 m • kg, 13 ft • lb)
lInstall the pad pin plug E and protector F.
T R..
Pad pin plug:
3 Nm (0.3 m • kg, 2.2 ft • lb)
Bolt (protector):
7 Nm (0.7 m • kg, 5.1 ft • lb)

3 - 32
INSP
ADJ
SPROCKETS INSPECTION/DRIVE CHAIN INSPECTION
SPROCKETS INSPECTION
1. Inspect:
lSprocket teeth a
Excessive wear ® Replace.
NOTE:
Replace the drive sprocket, rear wheel
sprocket and drive chain as a set.
EC369002
DRIVE CHAIN INSPECTION
1. Remove:
lMaster link clip
lJoint 1
lDrive chain 2
2. Clean:
lDrive chain
Place it in kerosene, and brush off as
much dirt as possible. Then remove the
chain from the kerosene and dry the
chain.
3. Measure:
lDrive chain length (10 links) a
Out of specification ® Replace.
Drive chain length (10 links):
: 152.5 mm (6.00 in)
4. Check:
lDrive chain stiffness a
Clean and oil the chain and hold as
illustrated.
Stiff ® Replace drive chain.

3 - 33
INSP
ADJ
DRIVE CHAIN SLACK ADJUSTMENT
5. Install:
lDrive chain 1
lJoint 2
lMaster link clip 3
CAUTION:
Be sure to install the master link clip to the
direction as shown.
aTurning direction
6. Lubricate:
lDrive chain
Drive chain lubricant:
SAE 10W-30 motor oil or suit-
able chain lubricants
EC36A060
DRIVE CHAIN SLACK ADJUSTMENT
1. Elevate the rear wheel by placing the
suitable stand under the engine.
2. Check:
lDrive chain slack a
Above the seal guard installation bolt.
Out of specification ® Adjust.
NOTE:
Before checking and/or adjusting, rotate the
rear wheel through several revolutions and
check the slack several times to find the tight-
est point. Check and/or adjust chain slack with
rear wheel in this “tight chain” position.
Drive chain slack:
40 ~ 50 mm (1.6 ~ 2.0 in)

3 - 34
INSP
ADJ
FRONT FORK INSPECTION
3. Adjust:
lDrive chain slack
Drive chain slack adjustment steps:
lLoosen the axle nut 1 and locknuts 2.
lAdjust chain slack by turning the adjusters
3.
To tighten ® Turn adjuster 3 counter-
clockwise.
To loosen ® Turn adjuster 3 clockwise
and push wheel forward.
lTurn each adjuster exactly the same
amount to maintain correct axle alignment.
(There are marks a on each side of chain
puller alignment.)
NOTE:
Turn the adjuster so that the chain is in line
with the sprocket, as viewed from the rear.
CAUTION:
Too small chain slack will overload the
engine and other vital parts; keep the
slack within the specified limits.
lTighten the axle nut while pushing down
the drive chain.
T R..
Axle nut:
125 Nm (12.5 m • kg, 90 ft • lb)
lTighten the locknuts.
EC36C000
FRONT FORK INSPECTION
1. Inspect:
lFront fork smooth action
Operate the front brake and stroke the
front fork.
Unsmooth action/oil leakage ® Repair
or replace.

3 - 38
INSP
ADJREAR SHOCK ABSORBER SPRING PRELOAD
ADJUSTMENT
EC36M013
REAR SHOCK ABSORBER SPRING
PRELOAD ADJUSTMENT
1. Elevate the rear wheel by placing the
suitable stand under the engine.
2. Remove:
lRear frame
3. Loosen:
lLocknut 1
4. Adjust:
lSpring preload
By turning the adjuster 2.
* For EUROPE
NOTE:
lBe sure to remove all dirt and mud from
around the locknut and adjuster before
adjustment.
lThe length of the spring (installed) changes
1.5 mm (0.06 in) per turn of the adjuster.
CAUTION:
Never attempt to turn the adjuster beyond
the maximum or minimum setting.
5. Tighten:
lLocknut
6. Install:
lRear frame Stiffer ®Increase the spring preload.
(Turn the adjuster 2 in.)
Softer ®Decrease the spring preload.
(Turn the adjuster 2 out.)
Spring length (installed) a:
Standard length Extent of adjustment
248 mm (9.76 in)
*262 mm (10.31 in)242 ~ 260 mm
(9.53 ~ 10.24 in)
*257 ~ 275 mm
(10.12 ~ 10.83 in)
T R..29 Nm (2.9 m · kg, 21 ft · lb)

3 - 42
INSP
ADJTIRE PRESSURE CHECK/SPOKES INSPECTION AND
TIGHTENING/WHEEL INSPECTION
EC36Q000
TIRE PRESSURE CHECK
1. Measure:
lTire pressure
Out of specification ® Adjust.
NOTE:
lCheck the tire while it is cold.
lLoose bead stoppers allow the tire to slip off
its position on the rim when the tire pressure
is low.
lA tilted tire valve stem indicates that the tire
slips off its position on the rim.
lIf the tire valve stem is found tilted, the tire is
considered to be slipping off its position. Cor-
rect the tire position.
Standard tire pressure:
100 kPa (1.0 kg/cm2, 15 psi)
EC36S002
SPOKES INSPECTION AND TIGHTENING
1. Inspect:
lSpokes 1
Bend/damage ® Replace.
Loose spoke ® Retighten.
2. Tighten:
lSpokes
NOTE:
Be sure to retighten these spokes before and
after break-in. After a practice or a race check
spokes for looseness.
T R..3 Nm (0.3 m · kg, 2.2 ft · lb)
EC36T000
WHEEL INSPECTION
1. Inspect:
lWheel runout
Elevate the wheel and turn it.
Abnormal runout ® Replace.