torque YAMAHA YZ250F 2001 Manuale duso (in Italian)

4 - 25
ENGCAMSHAFTS
CAUTION:
Do not turn the crankshaft during the
camshaft installation. Damage or
improper valve timing will result.
lInstall the clips, camshaft caps 4 and
bolts (camshaft cap) 5.
T R..
Bolt (camshaft cap):
10 Nm (1.0 m • kg, 7.2 ft • lb)
NOTE:
lBefore removing the clips, cover the cylin-
der head with a clean rag to prevent the
clips from into the cylinder head cavity.
lApply the engine oil on the thread and con-
tact surface of the bolts (camshaft cap).
lTighten the bolts (camshaft cap) 5 in a
crisscross pattern.
CAUTION:
The bolts (camshaft cap) must be tight-
ened evenly or damage to the cylinder
head, camshaft caps and camshaft will
result.
2. Install:
lTiming chain tensioner
Installation steps:
lWhile pressing the tensioner rod lightly
with fingers, use a thin screwdriver and
wind the tensioner rod up fully clockwise.
lWith the rod fully wound and the chain
tensioner UP mark a facing upward,
install the gasket 1 and the timing chain
tensioner 2, and tighten the bolt 3 to the
specified torque.
T R..
Bolt (timing chain tensioner):
10 Nm (1.0 m • kg, 7.2 ft • lb)

4 - 26
ENG
lRelease the screwdriver, check the ten-
sioner rod to come out and tighten the
gasket 4 and the cap bolt 5 to the speci-
fied torque.
T R..
Tensioner cap bolt:
7 Nm (0.7 m • kg, 5.1 ft • lb)
3. Turn:
lCrankshaft
Counterclockwise several turns
4. Check:
lRotor T.D.C. mark
Align with the crankcase align mark.
lCamshaft match marks
Align with the cylinder head surface.
Out of alignment ® Adjust.
5. Install:
lTiming mark accessing screw 1
lCrankshaft end accessing screw 2
6. Install:
lTiming chain guide (top side) 1
lCylinder head cover gasket 2
lCylinder head cover 3
lBolt (cylinder head cover) 4
NOTE:
Apply the sealant on the cylinder head cover
gasket.
Quick gasket®:
ACC-QUICK-GS-KT
YAMAHA Bond No. 1215:
90890-85505
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)
CAMSHAFTS

ENG
4 - 85
DEPOSE DU MOTEUR
MOTOR DEMONTIEREN
RIMOZIONE DEL MOTORE
2. Montieren:
lSicherungsscheibe 1
lMutter (Antriebsritzel) 2
HINWEIS:
Beim Festziehen der Mutter die Hin-
terradbremse betätigen.
T R..75 Nm (7,5 m · kg)
3. Die Lasche der Sicherungs-
scheibe umbiegen, um die
Mutter zu sichern.
4. Montieren:
lAntriebskettenritzel 1
lKettenschutz 2
lSchraube (Kettenschutz) 3
T R..10 Nm (1,0 m · kg)
Ölschlauch und Leerlaufschalter
1. Montieren:
lO-Ring 1
lPaßstift 2
lÖlschlauch 3
lSchraube (Ölschlauch) 4
HINWEIS:
Lithiumfett auf den O-Ring auftragen.
2. Montieren:
lFeder 1
lStift 2
lO-Ring 3
lLeerlaufschalter 4
lSchraube (Leerlaufschalter)
5
HINWEIS:
Lithiumfett auf den O-Ring auftragen.
T R..10 Nm (1,0 m · kg)
T R..4 Nm (0,4 m · kg)
2. Monter:
lRondelle-frein 1
lEcrou (pignon d’entraînement)
2
N.B.:
Serrer l’écrou en actionnant le frein
arrière.
T R..75 Nm (7,5 m · kg, 54 ft · lb)
3. Courber la languette de la ron-
delle-frein pour verrouiller
l’écrou.
4. Monter:
lGuide de pignon de chaîne de
transmission 1
lCouvercle de chaîne 2
lVis (couvercle de chaîne) 3
T R..10 Nm (1,0 m · kg, 7,2 ft · lb)
Durit d’huile et contacteur de point
mort
1. Monter:
lJoint torique 1
lGoujon 2
lDurit d’huile 3
lBoulon (durit d’huile) 4
N.B.:
Enduire le joint torique de graisse à base
de savon au lithium.
2. Monter:
lRessort 1
lGoupille 2
lJoint torque 3
lContacteur de point mort 4
lBoulon (contacteur de point
mort) 5
N.B.:
Enduire le joint torique de graisse à base
de savon au lithium.
T R..10 Nm (1,0 m · kg, 7,2 ft · lb)
T R..4 Nm (0,4 m · kg, 2,9 ft · lb)
2. Installare:
lRondella di bloccaggio 1
lDado (corona dentata trasmis-
sione) 2
NOTA:
Avvitare il dado agendo sul freno poste-
riore.
T R..75 Nm (7,5 m · kg, 54 ft · lb)
3. Piegare la linguetta della ron-
della di bloccaggio.
4. Installare:
lGuida corona catena di tra-
smissione 1
lCarterino corona catena di tra-
smissione 2
lVite (carterino corona catena di
trasmissione) 3
T R..10 Nm (1,0 m · kg, 7,2 ft · lb)
Flessibile dell’olio e interruttore di
folle
1. Installare:
lO-ring 1
lGrano di centraggio 2
lFlessibile dell’olio 3
lBullone (tubo flessibile
dell’olio) 4
NOTA:
Applicare grasso a base di sapone di litio
sull’O-ring.
2. Installare:
lMolla 1
lPerno 2
lO-ring 3
lInterruttore folle 4
lBullone (interruttore folle) 5
NOTA:
Applicare grasso a base di sapone di litio
sull’O-ring.
T R..10 Nm (1,0 m · kg, 7,2 ft · lb)
T R..4 Nm (0,4 m · kg, 2,9 ft · lb)

5 - 38
CHASFRONT FORK
26. Tighten:
lFront fork cap bolt (locknut) 1
NOTE:
lWhile compressing the fork spring, set the
thin type spanners 2 between the spacer 3
and spring guide 4.
lHold the locknut 5 and tighten the front fork
cap bolt with specified torque.
27. Install:
lFront fork cap bolt 1
To outer tube.
NOTE:
Temporarily tighten the cap bolt.
T R..29 Nm (2.9 m · kg, 21 ft · lb)
28. Install:
lProtector guide 1
Installation
1. Install:
lFront fork 1
NOTE:
lTemporarily tighten the pinch bolts (lower
bracket).
lDo not tighten the pinch bolts (upper bracket)
yet.
2. Tighten:
lFront fork cap bolt 1
3. Adjust:
lFront fork top end a
Front fork top end (standard) a:
5 mm (0.20 in)
T R..30 Nm (3.0 m · kg, 22 ft · lb)

5 - 39
CHASFRONT FORK
4. Tighten:
lPinch bolt (upper bracket) 1
lPinch bolt (lower bracket) 2
ACHTUNG:CAUTION:
Tighten the lower bracket to specified
torque. If torqued too much, it may cause
the front fork to malfunction.
5. Install:
lBrake hose holder 1
lBrake caliper 2
lBolt (brake caliper) 3
NOTE:
Fit the brake hose holder cut a over the pro-
jection b on the front fork and clamp the brake
hose.
6. Install:
lBrake hose holder 1
lBolt (brake hose holder) 2
lProtector 3
lBolt (protector) 4
NOTE:
When installing the brake hose holder, pass
the brake hose 5 in front of the axle boss a,
then fit it into the hose groove b so that the
brake hose does not contact the nut (wheel
axle).
T R..23 Nm (2.3 m · kg, 17 ft · lb)
T R..20 Nm (2.0 m · kg, 14 ft · lb)
T R..23 Nm (2.3 m · kg, 17 ft · lb)
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)
7. Adjust:
lRebound damping force
NOTE:
Turn in the damping adjuster 1 finger-tight
and then turn out to the originally set position.

5 - 49
CHASSTEERING
9. After tightening the nut, check the steer-
ing for smooth movement. If not, adjust
the steering by loosening the steering
ring nut little by little.
10. Adjust:
lFront fork top end a
Front fork top end (standard) a:
5 mm (0.20 in)
11. Tighten:
lPinch bolt (upper bracket) 1
lPinch bolt (lower bracket) 2
ACHTUNG:CAUTION:
Tighten the lower bracket to specified
torque. If torqued too much, it may cause
the front fork to malfunction.
T R..23 Nm (2.3 m · kg, 17 ft · lb)
T R..20 Nm (2.0 m · kg, 14 ft · lb)

7 - 21
TUNSETTING
EC72H002
Suspension setting
lFront fork
NOTE:
lIf any of the following symptoms is experienced with the standard position as the base, make
resetting by reference to the adjustment procedure given in the same chart.
lBefore any change, set the rear shock absorber sunken length to the standard figure 90 ~
100 mm (3.5 ~ 3.9 in).
SymptomSection
Check Adjust
JumpLarge
gapMedium
gapSmall
gap
Stiff over entire range
CCC
Compression damping
Oil level (oil amount)
SpringTurn adjuster counterclockwise (about 2 clicks) to
decrease damping.
Decrease oil level by about 5 ~ 10 mm (0.2 ~ 0.4 in).
Replace with soft spring.
Unsmooth movement
over entire range
CCCC
Outer tube
Inner tube
Under bracket tightening
torqueCheck for any bends, dents, and other noticeable
scars, etc. If any, replace affected parts.
Retighten to specified torque.
Poor initial
movement
C
Rebound damping
Oil sealTurn adjuster counterclockwise (about 2 clicks) to
decrease damping.
Apply grease in oil seal wall.
Soft over entire range,
bottoming out
CC
Compression damping
Oil level (oil amount)
SpringTurn adjuster clockwise (about 2 clicks) to increase
damping.
Increase oil level by about 5 ~ 10 mm (0.2 ~ 0.4 in).
Replace with stiff spring.
Stiff toward stroke end
COil level (oil amount) Decrease oil level by about 5 mm (0.2 in).
Soft toward stroke end,
bottoming out
COil level (oil amount) Increase oil level by about 5 mm (0.2 in).
Stiff initial movement
CCCCCompression dampingTurn adjuster counterclockwise (about 2 clicks) to
decrease damping.
Low front, tending to
lower front posture
CC
Compression damping
Rebound damping
Balance with rear end
Oil level (oil amount)Turn adjuster clockwise (about 2 clicks) to increase
damping.
Turn adjuster counterclockwise (about 2 clicks) to
decrease damping.
Set sunken length for 95 ~ 100 mm (3.7 ~ 3.9 in) when
one passenger is astride seat (lower rear posture).
Increase oil level by about 5 mm (0.2 in).
“Obtrusive” front, tend-
ing to upper front pos-
ture
CC
Compression damping
Balance with rear end
Spring
Oil lever (oil amount)Turn adjuster counterclockwise (about 2 clicks) to
decrease damping.
Set sunken length for 90 ~ 95 mm (3.5 ~ 3.7 in) when
one passenger is astride seat (upper rear posture).
Replace with soft spring.
Decrease oil level by about 5 ~ 10 mm (0.2 ~ 0.4 in).