2005 YAMAHA YZ250F oil

4 - 100
ENGTRANSMISSION, SHIFT CAM AND SHIFT FORK
5. Install:
Shift fork 1 (L) 1
Shift fork 2 (C) 2
Shift fork 3 (R) 3
Shift cam 4
To main axle and drive axle.
NOTE:
Apply the molybdenum disulfide oil on the
shift fork grooves.
Mesh the shift fork #1 (L) with the 4th wheel
gear 5 and #3 (R) with the 5th wheel gear 7
on the drive axle.
Mesh the shift fork #2 (C) with the 3rd pinion
gear 6 on the main axle.
6. Install:
Transmission assembly 1
To left crankcase 2.
NOTE:
Apply the engine oil on the bearings and guide
bars.
7. Check:
Shifter operation
Transmission operation
Unsmooth operation → Repair.

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
FRONT WHEEL REMOVAL
WARNING
Support the machine securely so
there is no danger of it falling over. Preparation for removal Hold the machine by placing the
suitable stand under the engine.
1 Bolt (axle holder) 4 Only loosening.
2 Nut (front wheel axle) 1
3 Front wheel axle 1
4 Front wheel 1
5 Collar 2
6 Oil seal 2
7 Bearing 2 Refer to “REMOVAL POINTS”.
8 Brake disc 1
2
31
3

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
REAR WHEEL REMOVAL
WARNING
Support the machine securely so
there is no danger of it falling over. Preparation for removal Hold the machine by placing the
suitable stand under the engine.
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”.
10 Brake disc 1
2
31
3
FRONT WHEEL AND REAR WHEEL

5 - 3
CHASFRONT WHEEL AND REAR WHEEL
EC593000
REMOVAL POINTS
EC523101
Rear wheel
1. Remove:
Wheel 1
NOTE:
Push the wheel forward and remove the drive
chain 2.
EC513201
Wheel bearing (if necessary)
1. Remove:
Bearing 1
NOTE:
Remove the bearing using a general bearing
puller 2.
EC594000
INSPECTION
EC514100
Wheel
1. Measure:
Wheel runout
Out of limit → Repair/replace.
2. Inspect:
Bearing
Rotate inner race with a finger.
Rough spot/seizure → Replace.
NOTE:
Replace the bearings, oil seal and wheel collar
as a set.
Wheel runout limit:
Radial
1: 2.0 mm (0.08 in)
Lateral
2: 2.0 mm (0.08 in)

5 - 3
CHAS
DEMONTAGE-EINZELHEITEN
Hinterrad
1. Demontieren:
Rad
1
HINWEIS:
Das Hinterrad nach vorn drücken
und die Antriebskette
2 abnehmen.
Radlager (nach Bedarf)
1. Demontieren:
Lager
1
HINWEIS:
Das Lager mit einem Lageraustreiber
2 ausbauen.
KONTROLLE
Rad
1. Messen:
Felgenschlag
Nicht nach Vorgabe
→ Instand
setzen/erneuern.
Max. Felgenschlag:
Höhenschlag 1:
2,0 mm (0,08 in)
Seitenschlag 2:
2,0 mm (0,08 in)
2. Kontrollieren:
Lager
Den Innenlaufring mit den Fin-
gern drehen.
Stockend/fest
→ Erneuern.
HINWEIS:
Lager, Dichtring und Distanzhülse
satzweise erneuern. POINTS DE DEPOSE
Roue arrière
1. Déposer:
Roue 1
N.B.:
Pousser la roue vers l’avant et déposer la
chaîne de transmission 2.
Roulement de roue (si nécessaire)
1. Déposer:
Roulement 1
N.B.:
Déposer le roulement à l’aide d’un arra-
che-roulement courant 2.
CONTROLE
Roue
1. Mesurer:
Voile de roue
Hors spécifications → Réparer/
remplacer.
Limite de voile de roue:
Radial 1:
2,0 mm (0,08 in)
Latéral 2:
2,0 mm (0,08 in)
2. Contrôler:
Roulement
Faire tourner la cage interne avec
le doigt.
Rugosité/grippage → Remplacer.
N.B.:
Remplacer ensemble les roulements, la
bague d’étanchéité et l’entretoise épau-
lée de roue.PUNTI DI RIMOZIONE
Ruota posteriore
1. Togliere:
Ruota 1
NOTA:
Spingere la ruota in avanti e togliere la
catena di trasmissione 2.
Cuscinetto della ruota (se necessario)
1. Togliere:
Cuscinetto 1
NOTA:
Togliere il cuscinetto con un normale
estrattore di cuscinetti 2.
CONTROLLO
Ruota
1. Misurare:
Scentratura ruota
Fuori limite → Riparare/sostituire.
Limite di disassamento della
ruota:
Radiale 1:
2,0 mm (0,08 in)
Laterale 2:
2,0 mm (0,08 in)
2. Controllare:
Cuscinetto
Ruotare la pista interna con un
dito.
Punto ruvido/blocco → Sostitu-
ire.
NOTA:
Sostituire i cuscinetti, il paraolio e il col-
larino della ruota in blocco.
ROUE AVANT ET ROUE ARRIERE
VORDER- UND HINTERRAD
RUOTA ANTERIORE E POSTERIORE

5 - 4
CHAS
Radachse
1. Messen:
Radachs-Verbiegung
Nicht nach Vorgabe
→ Erneu-
ern.
Eine Meßuhr
1 verwenden.
HINWEIS:
Der von der Meßuhr angezeigte Wert
ist zu halbieren, um den Wert der
Verbiegung zu erhalten.
WARNUNG
Eine verbogene Radachse darf
unter keinen Umständen gerichtet
werden.
Max. Radachs-Verbie-
gung:
0,5 mm (0,020 in)
Bremsscheibe
1. Messen:
Bremsscheiben-Verzug (nur
Hinterrad)
Eine Meßuhr
1 verwenden.
Nicht nach Vorgabe
→ Fel-
genschlag kontrollieren.
Falls Felgenschlag in Ordnung
ist, die Bremsscheibe erneu-
ern.
2. Messen:
Bremsscheiben-Stärke
a
Nicht nach Vorgabe
→ Erneu-
ern.
Max. Bremsscheiben-
Verzug:
Hinten:
:
0,15 mm (0,006 in)
Bremsscheiben-Stärke:
Vorn:
3,0 mm (0,12 in)
:
2,5 mm (0,10 in)
Hinten:
4,0 mm (0,16 in)
:
3,5 mm (0,14 in)
Axe de roue
1. Mesurer:
Déformations de l’axe de roue
Hors spécifications → Rempla-
cer.
Utiliser le comparateur à cadran
1.
N.B.:
La valeur de flexion est égale à la moitié
de la valeur affichée sur le comparateur à
cadran.
AVERTISSEMENT
Ne pas tenter de redresser un axe
déformé.
Limite de flexion d’axe de
roue:
0,5 mm (0,020 in)
Disque de frein
1. Mesurer:
Déflexion du disque de frein (dis-
que de frein arrière seulement)
Utiliser le comparateur à cadran
1.
Hors spécifications → Contrôler
le voile de roue.
Si le voile de roue est normal,
remplacer le disque de frein.
2. Mesurer:
Epaisseur du disque de frein a
Hors spécifications → Rempla-
cer.
Limite de déflexion du dis-
que de frein:
Arrière:
:
0,15 mm (0,006 in)
Epaisseur du disque de
frein:
Avant:
3,0 mm (0,12 in)
:
2,5 mm (0,10 in)
Arrière:
4,0 mm (0,16 in)
:
3,5 mm (0,14 in)
Asse della ruota
1. Misurare:
Deformazioni dell’asse della
ruota
Non conforme alle specifiche →
Sostituire.
Utilizzare un comparatore 1.
NOTA:
Il valore di piegatura corrisponde a metà
della lettura del comparatore.
AVVERTENZA
Non tentare di raddrizzare un asse
deformato.
Limite di piegatura
dell’asse della ruota:
0,5 mm (0,020 in)
Disco freno
1. Misurare:
Deflessione del disco del freno
(solo disco posteriore)
Utilizzare un comparatore 1.
Non conforme alle specifiche →
Controllare la scentratura ruota.
Se la scentratura è in buone con-
dizioni, sostituire il disco del
freno.
2. Misurare:
Spessore del disco freno a
Non conforme ai limiti → Sosti-
tuire.
Limite di deflessione del
disco del freno:
Posteriore:
:
0,15 mm (0,006 in)
Spessore del disco freno:
Anteriore:
3,0 mm (0,12 in)
:
2,5 mm (0,10 in)
Posteriore:
4,0 mm (0,16 in)
:
3,5 mm (0,14 in)
ROUE AVANT ET ROUE ARRIERE
VORDER- UND HINTERRAD
RUOTA ANTERIORE E POSTERIORE

5 - 5
CHASFRONT WHEEL AND REAR WHEEL
EC595000
ASSEMBLY AND INSTALLATION
Front wheel
1. Install:
Bearing (left) 1
Spacer 2
Bearing (right) 3
Oil seal 4
NOTE:
Apply the lithium soap base grease on the
bearing and oil seal lip when installing.
Use a socket that matches the outside diam-
eter of the race of the bearing.
Left side of bearing shall be installed first.
Install the oil seal with its manufacture’s
marks or numbers facing outward.
CAUTION:
Do not strike the inner race of the bearing.
Contact should be made only with the outer
race.
2. Install:
Brake disc 1
Bolt (brake disc) 2
NOTE:
Tighten the bolts in stage, using a crisscross
pattern.
T R..12 Nm (1.2 m · kg, 8.7 ft · lb)
3. Install:
Collar 1
NOTE:
Apply the lithium soap base grease on the oil
seal lip.
Install the collars with their projections a
facing the wheel.
4. Install:
Wheel
NOTE:
Install the brake disc 1 between the brake
pads 2 correctly.

5 - 7
CHASFRONT WHEEL AND REAR WHEEL
Rear wheel
1. Install:
Bearing (right) 1
Circlip 2
Spacer 3
Bearing (left) 4
Oil seal 5
NOTE:
Apply the lithium soap base grease on the
bearing and oil seal lip when installing.
Install the bearing with seal facing outward.
Use a socket that matches the outside diam-
eter of the race of the bearing.
Right side of bearing shall be installed first.
Install the oil seal with its manufacture’s
marks or numbers facing outward.
CAUTION:
Do not strike the inner race of the bearing.
Contact should be made only with the outer
race.
2. Install:
Brake disc 1
Bolt (brake disc) 2
NOTE:
Tighten the bolts in stage, using a crisscross
pattern.
T R..14 Nm (1.4 m · kg, 10 ft · lb)
3. Install:
Rear wheel sprocket 1
Bolt (rear wheel sprocket) 2
Washer (rear wheel sprocket) 3
Nut (rear wheel sprocket) 4
NOTE:
Tighten the nuts in stage, using a crisscross
pattern.
T R..42 Nm (4.2 m · kg, 30 ft · lb)