2002 YAMAHA YZ250F torque

SPEC
2 - 17
EC220001
GENERAL TORQUE SPECIFICATIONS
This chart specifies torque for standard fasten-
ers with standard I.S.O. pitch threads. Torque
specifications for special components or
assemblies are included in the applicable sec-
tions of this book. To avoid warpage, tighten
multi-fastener assemblies in a crisscross fash-
ion, in progressive stages, until full torque is
reached. Unless otherwise specified, torque
specifications call for clean, dry threads. Com-
ponents should be at room temperature.
A: Distance between flats
B: Outside thread diameter
EC230000
DEFINITION OF UNITS
A
(Nut)B
(Bolt)TORQUE
SPECIFICATION
Nm m•kg ft•lb
10 mm
12 mm
14 mm
17 mm
19 mm
22 mm6 mm
8 mm
10 mm
12 mm
14 mm
16 mm6
15
30
55
85
1300.6
1.5
3.0
5.5
8.5
134.3
11
22
40
61
94
Unit Read Definition Measure
mm
cmmillimeter
centimeter10
-3 meter
10-2 meterLength
Length
kg kilogram 10
3 gram Weight
N Newton 1 kg × m/sec
2 Force
Nm
m • kgNewton meter
Meter kilogramN × m
m × kgTorque
Torque
Pa Pascal N/m
2Pressure
N/mm Newton per millimeter N/mm Spring rate
L
cm
3 Liter
Cubic centimeter—
—Volume or capacity
Volume or capacity
r/min Revolution per minute—Engine speed
GENERAL TORQUE SPECIFICATIONS/
DEFINITION OF UNITS

3 - 44
INSP
ADJ
STEERING HEAD INSPECTION AND ADJUSTMENT
Tighten 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)
Loosen the steering ring nut one turn.
Retighten 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)
Check the steering stem by turning it lock
to lock. If there is any binding, remove the
steering stem assembly and inspect the
steering bearings.
Install the upper bracket 5, steering stem
nut 6, handlebar 7, handlebar upper
holder 8 and number plate 9.
NOTE:
The upper handlebar holder should be
installed with the punched mark a for-
ward.
Insert 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 stem nut:
145 Nm (14.5 m • kg, 105 ft • lb)
Handlebar upper holder:
28 Nm (2.8 m • kg, 20 ft • lb)
Pinch bolt (upper bracket):
23 Nm (2.3 m • kg, 17 ft • lb)
Number plate:
7 Nm (0.7 m • kg, 5.1 ft • lb)

4 - 26
ENGCAMSHAFTS
CAUTION:
Do not turn the crankshaft during the
camshaft installation. Damage or
improper valve timing will result.
Install 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:
Before removing the clips, cover the cylin-
der head with a clean rag to prevent the
clips from into the cylinder head cavity.
Apply the engine oil on the thread and con-
tact surface of the bolts (camshaft cap).
Tighten 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:
Timing chain tensioner
Installation steps:
While pressing the tensioner rod lightly
with fingers, use a thin screwdriver and
wind the tensioner rod up fully clockwise.
With 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 - 27
ENG
Release 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:
Crankshaft
Counterclockwise several turns.
4. Check:
Rotor T.D.C. mark
Align with the crankcase align mark.
Camshaft match marks
Align with the cylinder head surface.
Out of alignment → Adjust.
5. Install:
Timing mark accessing screw 1
Crankshaft end accessing screw 2
6. Install:
Timing chain guide (top side) 1
Cylinder head cover gasket 2
Cylinder head cover 3
Bolt (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 - 86
DEPOSE DU MOTEUR
MOTOR DEMONTIEREN
RIMOZIONE DEL MOTORE
2. Montieren:
Sicherungsscheibe 1
Mutter (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:
Antriebskettenritzel 1
Kettenschutz 2
Schraube (Kettenschutz) 3
T R..8 Nm (0,8 m · kg)
Ölschlauch und Leerlaufschalter
1. Montieren:
O-Ring 1
Paßstift 2
Ölschlauch 3
Schraube (Ölschlauch) 4
HINWEIS:
Lithiumfett auf den O-Ring auftragen.
2. Montieren:
Feder 1
Stift 2
O-Ring 3
Leerlaufschalter 4
Schraube (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:
Rondelle-frein 1
Ecrou (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:
Guide de pignon de chaîne de
transmission 1
Couvercle de chaîne 2
Vis (couvercle de chaîne) 3
T R..8 Nm (0,8 m · kg, 5,8 ft · lb)
Durit d’huile et contacteur de point
mort
1. Monter:
Joint torique 1
Goujon 2
Durit d’huile 3
Boulon (durit d’huile) 4
N.B.:
Enduire le joint torique de graisse à base
de savon au lithium.
2. Monter:
Ressort 1
Goupille 2
Joint torque 3
Contacteur de point mort 4
Vis (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:
Rondella di bloccaggio 1
Dado (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:
Guida corona catena di tra-
smissione 1
Carterino corona catena di tra-
smissione 2
Vite (carterino corona catena di
trasmissione) 3
T R..8 Nm (0,8 m · kg, 5,8 ft · lb)
Flessibile dell’olio e interruttore di
folle
1. Installare:
O-ring 1
Grano di centraggio 2
Flessibile dell’olio 3
Bullone (tubo flessibile
dell’olio) 4
NOTA:
Applicare grasso a base di sapone di litio
sull’O-ring.
2. Installare:
Molla 1
Perno 2
O-ring 3
Interruttore folle 4
Vite (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:
Front fork cap bolt (locknut) 1
NOTE:
While compressing the fork spring, set the
thin type spanners 2 between the spacer 3
and spring guide 4.
Hold the locknut 5 and tighten the front fork
cap bolt with specified torque.
27. Install:
Front 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:
Protector guide 1
Installation
1. Install:
Front fork 1
NOTE:
Temporarily tighten the pinch bolts (lower
bracket).
Do not tighten the pinch bolts (upper bracket)
yet.
2. Tighten:
Front fork cap bolt 1
3. Adjust:
Front 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:
Pinch bolt (upper bracket) 1
Pinch 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:
Brake hose holder 1
Brake caliper 2
Bolt (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:
Brake hose holder 1
Bolt (brake hose holder) 2
Protector 3
Bolt (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:
Rebound damping force
NOTE:
Turn in the damping adjuster 1 finger-tight
and then turn out to the originally set position.

5 - 50
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:
Front fork top end a
Front fork top end (standard) a:
5 mm (0.20 in)
11. Tighten:
Pinch bolt (upper bracket) 1
Pinch 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)