2007 YAMAHA YZ250F oil

INSP
ADJ
REIFENLUFTDRUCK
KONTROLLIEREN
1. Messen:
Reifenluftdruck
Nicht nach Vorgabe → Einstel-
len.
HINWEIS:
Den Reifenluftdruck bei kaltem
Reifen kontrollieren.
Bei zu niedrigem Reifenluftdruck
besteht die Gefahr, dass der Rei-
fen auf der Felge rutscht.
Ein schräg stehender Ventilschaft
deutet darauf hin, dass der Reifen
sich verschoben hat.
Falls der Ventilschaft schräg steht,
sitzt der Reifen falsch auf. In die-
sem Fall die Reifenlage korrigieren.
Standard-Reifenluft-
druck:
100 kPa
(1,0 kgf/cm
2, 15 psi)
SPEICHEN KONTROLLIEREN UND
SPANNEN
1. Kontrollieren:
Speichen 1
Verbogen/beschädigt →
Erneuern.
Speiche lose → Spannen.
2. Festziehen:
Speichen
HINWEIS:
Die Speichen müssen vor und nach
dem Einfahren gespannt und nach
jeder Fahrt kontrolliert werden.
T R..3 Nm (0,3 m · kg, 2,2 ft · lb)
RÄDER KONTROLLIEREN
1. Kontrollieren:
Felgenschlag
Das Rad anheben und dre-
hen.
Anormaler Schlag → Erneu-
ern. CONTROLE DE LA PRESSION DES
PNEUS
1. Mesurer:
Pression des pneus
Hors spécifications → Régler.
N.B.:
Contrôler les pneus à froid.
Le pneu risque de se déjanter si le
gonflage est insuffisant.
Une tige de valve de pneu inclinée
indique que le pneu est mal assis.
Une tige de valve de pneu inclinée
indique que le pneu est mal assis. Cor-
riger la position du pneu.
Pression des pneus stan-
dard:
100 kPa
(1,0 kgf/cm
2, 15 psi)
CONTROLE ET SERRAGE DES
RAYONS
1. Contrôler:
Rayons 1
Déformation/endommagement →
Remplacer.
Rayon desserré → Resserrer.
2. Serrer:
Rayons
N.B.:
Veiller à resserrer ces rayons avant et
après le rodage. Après tout entraînement
ou toute course, contrôler la tension des
rayons.
T R..3 Nm (0,3 m · kg, 2,2 ft · lb)
CONTROLE DES ROUES
1. Contrôler:
Voile de roue
Surélever la roue et la faire tour-
ner.
Voile excessif → Remplacer.CONTROLLO PRESSIONE DEI
PNEUMATICI
1. Misurare:
Pressione dei pneumatici
Non conforme alle specifiche →
Regolare.
NOTA:
Controllare il pneumatico quando è
freddo.
Se gli elementi di arresto del tallone
sono lenti, il pneumatico scivola via
dalla sua posizione sul cerchio quando
la pressione è bassa.
La valvola del pneumatico inclinata
indica che il pneumatico scivola via
dalla sua posizione sul cerchio.
Se si nota che la valvola del pneuma-
tico è inclinata, il pneumatico è fuori
posizione. Correggere la posizione del
pneumatico.
Pressione standard dei
pneumatici:
100 kPa
(1,0 kgf/cm
2, 15 psi)
CONTROLLO E SERRAGGIO DEI
RAGGI
1. Controllare:
Raggi 1
Deformazioni/danni → Sostituire.
Raggio lento → Serrare.
2. Serrare:
Raggi
NOTA:
Assicurarsi di serrare i raggi prima e
dopo il rodaggio. Dopo l’utilizzo o dopo
una competizione, controllare che i raggi
non siano lenti.
T R..3 Nm (0,3 m · kg, 2,2 ft · lb)
CONTROLLO DELLE RUOTE
1. Controllare:
Scentratura ruota
Sollevare la ruota e farla ruotare.
Scentratura anomala → Sostitu-
ire.
CONTROLE DE LA PRESSION DES PNEUS/
CONTROLE ET SERRAGE DES RAYONS/CONTROLE DES ROUES
REIFENLUFTDRUCK KONTROLLIEREN/
SPEICHEN KONTROLLIEREN UND SPANNEN/RÄDER KONTROLLIEREN
CONTROLLO PRESSIONE DEI PNEUMATICI/
CONTROLLO E SERRAGGIO DEI RAGGI/CONTROLLO DELLE RUOTE
3 - 40

3 - 44
INSP
ADJ
LUBRICATION
LUBRICATION
To ensure smooth operation of all compo-
nents, lubricate your machine during setup,
after break-in, and after every race.
1All control cable
2Clutch lever pivot
3Shift pedal pivot
4Footrest pivot
5Throttle-to-handlebar contact
6Drive chain
7Tube guide cable winding portion
8Throttle cable end
9Clutch cable end
0Hot starter cable end
ÈUse Yamaha cable lube or equivalent on these
areas.
ÉUse SAE 10W-30 motor oil or suitable chain
lubricants.
ÊLubricate the following areas with high quality,
lightweight lithium-soap base grease.
CAUTION:
Wipe off any excess grease, and avoid get-
ting grease on the brake discs.
AAA
AAB
CC

3 - 46
INSP
ADJ
IGNITION TIMING CHECK
IGNITION TIMING CHECK
1. Remove:
Timing mark accessing screw 1
2. Attach:
Timing light
Inductive tachometer
To the ignition coil lead (orange lead 1).
Timing light:
YM-33277-A/90890-03141
1
3. Adjust:
Engine idling speed
Refer to “ENGINE IDLING SPEED
ADJUSTMENT” section.
4. Check:
Ignition timing
Visually check the stationary pointer a is
within the firing range b on the rotor.
Incorrect firing range → Check rotor and
pickup assembly.
5. Install:
Timing mark accessing screw

4 - 27
ENGCAMSHAFTS
Decompression system
1. Check:
Decompression system
Timing chain tensioner
1. Check:
While pressing the tensioner rod lightly
with fingers, use a thin screwdriver 1
and wind the tensioner rod up fully clock-
wise.
When releasing the screwdriver by press-
ing lightly with fingers, make sure that the
tensioner rod will come out smoothly.
If not, replace the tensioner assembly.
ASSEMBLY AND INSTALLATION
Camshaft
1. Install:
Exhaust camshaft 1
Intake camshaft 2 Checking steps:
Check that the decompression mecha-
nism cam 1 moves smoothly.
Check that the decompression mecha-
nism cam lever pin 2 projects from the
camshaft.
Installation steps:
Turn the crankshaft counterclockwise with
a wrench.
NOTE:
Apply the molybdenum disulfide oil on the
camshafts.
Apply the engine oil on the decompression
system.
Squeezing the decompression lever
allows the crankshaft to be turned easily.
Align the T.D.C. mark a on the rotor with
the align mark b on the crankcase cover
when piston is at T.D.C. on compression
stroke.

4 - 28
ENGCAMSHAFTS
Fit the timing chain 3 onto both camshaft
sprockets and install the camshafts on the
cylinder head.
NOTE:
The camshafts should be installed onto the
cylinder head so that the punch mark c on
the exhaust camshaft and the punch mark
d on the intake camshaft must align with
the cylinder head surface, as shown in the
illustration.
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 molybdenum disulfide oil on the
thread of the bolts (camshaft cap).
Tighten the bolts to the specified torque in
two or three steps in the proper tightening
sequence as shown.
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.

4 - 31
ENGCYLINDER HEAD
CYLINDER HEAD
Extent of removal:
1 Cylinder head removal
Extent of removal Order Part name Q’ty Remarks
CYLINDER HEAD REMOVAL
Preparation for removal Seat and fuel tank Refer to “SEAT, FUEL TANK AND SIDE
COVERS” section.
Exhaust pipe and silencer Refer to “EXHAUST PIPE AND
SILENCER” section.
Radiator hose 1 Disconnect at cylinder head side.
Carburetor Refer to “CARBURETOR” section.
Camshaft Refer to “CAMSHAFTS” section.
Upper engine bracket Refer to “ENGINE REMOVAL” section.
1 Radiator pipe 1
2 Oil delivery pipe 1
3Nut 2
4 Bolt [L = 135 mm (5.31 in)] 2
5 Bolt [L = 145 mm (5.71 in)] 2
6 Cylinder head 1
7 Timing chain guard (exhaust
side)1
1

4 - 33
ENGCYLINDER HEAD
ASSEMBLY AND INSTALLATION
Cylinder head
1. Install:
Dowel pin 1
Cylinder head gasket 2
Timing chain guide (exhaust side) 3
Cylinder head 4
NOTE:
While pulling up the timing chain, install the
timing chain guide (exhaust side) and cylinder
head.
2. Install:
Washer 1
Cable guide 2
Bolts [L = 145 mm (5.71 in)] 3
Bolts [L = 135 mm (5.31 in)] 4
Nuts 5
NOTE:
Apply the molybdenum disulfide grease on
the thread and contact surface of the bolts.
Follow the numerical order shown in the illus-
tration. Tighten the bolts and nuts in two
stages.
T R..38 Nm (3.8 m · kg, 27 ft · lb)
T R..38 Nm (3.8 m · kg, 27 ft · lb)
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)
3. Install:
Copper washer 1
Oil delivery pipe 2
Union bolt (M8) 3
Union bolt (M10) 4
T R..18 Nm (1.8 m · kg, 13 ft · lb)
T R..20 Nm (2.0 m · kg, 14 ft · lb)
4. Install:
Radiator pipe 1
Bolt (radiator pipe) 2
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)

4 - 38
ENGVALVES AND VALVE SPRINGS
5. Measure:
Runout (valve stem)
Out of specification → Replace.
NOTE:
When installing a new valve always replace
the guide.
If the valve is removed or replaced always
replace the oil seal.
6. Eliminate:
Carbon deposits
(from the valve face and valve seat)
7. Inspect:
Valve seat
Pitting/wear → Reface the valve seat.
Runout limit:
0.01 mm (0.0004 in)
8. Measure:
Valve seat width a
Out of specification → Reface the valve
seat.
Valve seat width:
Intake:
0.9 ~ 1.1 mm
(0.0354 ~ 0.0433 in)
: 1.6 mm (0.0630 in)
Exhaust:
0.9 ~ 1.1 mm
(0.0354 ~ 0.0433 in)
: 1.6 mm (0.0630 in)
Measurement steps:
Apply Mechanic’s blueing dye (Dykem) b
to the valve face.
Install the valve into the cylinder head.
Press the valve through the valve guide
and onto the valve seat to make a clear
pattern.
Measure the valve seat width. Where the
valve seat and valve face made contact,
blueing will have been removed.
If the valve seat is too wide, too narrow, or
the seat is not centered, the valve seat
must be refaced.