engine YAMAHA WR 250F 2006 Owners Manual

4 - 251
ENGCRANKCASE AND CRANKSHAFT
6. Tighten:
Hose guide
1
Clutch cable holder
2
Bolt (crankcase)
3
NOTE:Tighten the crankcase tightening
bolts in stage, using a crisscross pat-
tern.
T R..12 Nm (1.2 m · kg, 8.7 ft · lb)
7. Install:
Oil delivery pipe 2
1
O-ring
2
Bolt (oil delivery pipe 2)
3
NOTE:Apply the lithium soap base grease
on the O-rings.
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)
New
8. Install:
Timing chain
1
Timing chain guide
(intake side)
2
Bolt (timing chain guide)
3
9. Remove:
Sealant
Forced out on the cylinder
mating surface.
10. Apply:
Engine oil
To the crank pin, bearing and
oil delivery hole.
11. Check:
Crankshaft and transmission
operation.
Unsmooth operation
→
Repair.
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)
6. Serrer:
Guide de durit 1
Support du câble d’embrayage 2
Boulon (carter) 3
N.B.:
Serrer les boulons de serrage du carter
par étapes et en procédant en croix.
T R..12 Nm (1,2 m · kg, 8,7 ft · lb)
7. Monter:
Tuyau d’huile 2 1
Joint torique 2
Boulon (tuyau d’huile 2 ) 3
N.B.:
Appliquer de la graisse à savon de
lithium sur les joints toriques.
T R..10 Nm (1,0 m · kg, 7,2 ft · lb)
New
8. Monter:
Chaîne de distribution 1
Patin de chaîne de distribution
(côté admission) 2
Boulon (patin de chaîne de distri-
bution) 3
9. Déposer:
Pâte d’étanchéité
Répandue sur la surface de con-
tact du cylindre.
10. Appliquer:
Huile moteur
Sur le maneton de bielle, le roule-
ment et le trou d’huile.
11. Contrôler:
Fonctionnement du vilebrequin et
de la boîte de vitesses.
Fonctionnement irrégulier →
Réparer.
T R..10 Nm (1,0 m · kg, 7,2 ft · lb)
CARTER MOTEUR ET VILEBREQUIN

4 - 253
ENGTRANSMISSION, SHIFT CAM AND SHIFT FORK
EC4H0000
TRANSMISSION, SHIFT CAM AND SHIFT FORK
Extent of removal:
1 Shift fork, shift cam, main axle and drive axle removal
Extent of removal Order Part name Q’ty Remarks
TRANSMISSION, SHIFT CAM AND
SHIFT FORK REMOVAL
Preparation for removal Engine Refer to “ENGINE REMOVAL” section.
Separate the crankcase. Refer to “CRANKCASE AND CRANKSHAFT”
section.
1 Main axle 1
Refer to “REMOVAL POINTS”. 2 Drive axle 1
3 Shift cam 1
4 Shift fork 3 1
5 Shift fork 2 1
6 Shift fork 1 1
7 Collar 1
1

4 - 263
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. Monter:
Fourchette de sélection 1 (G) 1
Fourchette 2 (C) 2
Fourchette 3 (D) 3
Tambour 4
Sur l’arbre primaire et l’arbre
secondaire.
N.B.:
Appliquer de l’huile au bisulfure de
molybdène sur les gorges des four-
chettes de sélection.
Engrener la fourchette de sélection
n°1 (G) avec le pignon de 4ème 5 et
la fourchette n°3 (D) avec le pignon de
5ème 7 de l’arbre secondaire.
Engrener la fourchette n°2 (C) avec le
pignon de 3ème 6 de l’arbre princi-
pal.
6. Monter:
Boîte de vitesses complète 1
Sur le carter gauche 2.
N.B.:
Appliquer de l’huile moteur sur les rou-
lements et les barres de guidage.
7. Contrôler:
Fonctionnement du sélecteur
Fonctionnement de la boîte de
vitesses
Fonctionnement irrégulier →
Réparer.
BOITE DE VITESSES, TAMBOUR ET FOURCHETTES DE SELECTION

5 - 1
CHASFRONT WHEEL AND REAR WHEEL
EC500000
CHASSIS
EC590000
FRONT WHEEL AND REAR WHEEL
EC598000FRONT 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 nodanger 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 Speed sensor 1
6 Collar 1
7 Oil seal 1
8 Bearing 2 Refer to “REMOVAL POINTS”.
9 Brake disc 1
1
2
3
3

5 - 5
CHASFRONT WHEEL AND REAR WHEEL
EC598100REAR 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 nodanger 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
1
2
3
3

5 - 23
CHASFRONT BRAKE AND REAR BRAKE
EC5A0000
FRONT BRAKE AND REAR BRAKE
EC5A8000FRONT BRAKE
Extent of removal:
1 Brake hose removal
2 Brake caliper removal
3 Brake master cylinder removal
Extent of removal Order Part name Q’ty Remarks
FRONT BRAKE REMOVAL
WARNING
Support the machine securely so there is nodanger of it falling over. Preparation for removal Hold the machine by placing the suitable
stand under the engine.
Drain the brake fluid. Refer to “REMOVAL POINTS”.
1 Brake hose holder (protector) 2
2 Brake hose holder (brake caliper) 1
3 Union bolt 2
4 Brake hose 1
5 Pad pin plug 1 Remove when loosening the pad pin.
6 Pad pin 1 Loosen when disassembling the brake caliper.
7 Brake caliper 1
8 Brake lever 1
9 Brake master cylinder bracket 1
10 Brake master cylinder 1
12
2
3
3

5 - 27
CHASFRONT BRAKE AND REAR BRAKE
EC5A8100REAR BRAKE
Extent of removal:
1 Brake master cylinder removal
2 Brake hose removal
3 Brake caliper removal
Extent of removal Order Part name Q’ty Remarks
REAR BRAKE REMOVAL
WARNING
Support the machine securely so there is nodanger of it falling over. Preparation for removal Hold the machine by placing the suitable
stand under the engine.
Rear wheel Refer to “FRONT WHEEL AND REAR WHEEL”
section.
Drain the brake fluid. Refer to “REMOVAL POINTS”.
1 Brake pedal 1
2 Brake master cylinder 1
3 Brake hose holder 2
4 Union bolt 2
5 Brake hose 1
6 Pad pin plug 1 Remove when loosening the pad pin.
7 Pad pin 1 Loosen when disassembling the brake caliper.
8 Brake caliper 1
1
13
3
2

5 - 61
CHASFRONT FORK
EC550000
FRONT FORK
Extent of removal:
1 Front fork removal
Extent of removal Order Part name Q’ty Remarks
FRONT FORK REMOVAL
WARNING
Support the machine securely so there is nodanger of it falling over. Preparation for removal Hold the machine by placing the suitable
stand under the engine.
Front wheel Refer to “FRONT WHEEL AND REAR WHEEL”
section.
Front brake caliper Refer to “FRONT BRAKE AND REAR BRAKE”
section.
Headlight
Handlebar Refer to “HANDLEBAR” section.
1 Protector 1
2 Pinch bolt (upper bracket) 2 Only loosening.
3 Cap bolt 1 Loosen when disassembling the front fork.
4 Pinch bolt (lower bracket) 2 Only loosening.
5 Front fork 1
1

5 - 91
CHASHANDLEBAR
EC5B0000
HANDLEBAR
Extent of removal:
1 Handlebar removal
Extent of removal Order Part name Q’ty Remarks
Preparation for removalHANDLEBAR REMOVAL
Headlight
1 Hot starter cable 1 Disconnect at the lever side.
2 Hot starter lever holder 1
3 Clutch cable 1 Disconnect at the lever side.
4 Clutch lever holder 1 Disconnect the clutch switch lead.
5 Engine stop switch 1 Disconnect the engine stop switch lead.
6 Brake master cylinder 1 Refer to “REMOVAL POINTS”.
7 Start switch 1 Disconnect the start switch lead.
8 Throttle cable cap 1
9 Throttle cable #1 (pulled) 1 Disconnect at the throttle side.
10 Throttle cable #2 (pushed) 1 Disconnect at the throttle side.
11 Right grip 1 Refer to “REMOVAL POINTS”.
12 Tube guide 1
13 Left grip 1 Refer to “REMOVAL POINTS”.
14 Handlebar upper holder 2
15 Handlebar 1
16 Handlebar lower holder 2
1

5 - 103
CHAS
11. Install:
•Engine stop switch
1
•Clutch lever holder
2
•Bolt (clutch lever holder)
3
•Hot starter lever holder
4
•Bolt
(hot starter lever holder)
5
•Clamp
6
NOTE:•The engine stop switch, clutch
lever holder and clamp should be
installed according to the dimen-
sions shown.
•Pass the engine stop switch lead in
the middle of the clutch lever
holder.
T R..4 Nm (0.4 m · kg, 2.9 ft · lb)
T R..4 Nm (0.4 m · kg, 2.9 ft · lb)
12. Install:
•Clutch cable
1
•Hot starter cable
2
NOTE:Apply the lithium soap base grease
on the clutch cable end and hot
starter cable end.
13. Adjust:
•Clutch lever free play
Refer to “CLUTCH ADJUST-
MENT” section in the CHAP-
TER 3.
•Hot starter lever free play
Refer to “HOT STARTER
LEVER ADJUSTMENT” sec-
tion in the CHAPTER 3.
14. Fasten the hot starter cable
1
and clutch cable
2 with a clamp
3.
1
2
3
11. Monter:
Coupe-circuit du moteur 1
Support du levier d’embrayage
2
Boulon (support du levier
d’embrayage) 3
Support du levier de démarrage à
chaud 4
Boulon
(support du levier de démarrage à
chaud) 5
Collier 6
N.B.:
Monter le coupe-circuit du moteur, le
support du levier d’embrayage et le
collier en respectant les dimensions
indiquées.
Faire passer le fil du coupe-circuit du
moteur au milieu du support du levier
d’embrayage.
T R..4 Nm (0,4 m · kg, 2,9 ft · lb)
T R..4 Nm (0,4 m · kg, 2,9 ft · lb)
12. Monter:
Câble d’embrayage 1
Câble de démarrage à chaud 2
N.B.:
Appliquer de la graisse à savon de lithium
sur les extrémités du câble d’embrayage
et du câble de démarrage à chaud.
13. Régler:
Jeu du levier d’embrayage
Se reporter à la section “REGLAGE
DE L’EMBRAYAGE” au CHAPI-
TRE 3.
Jeu du levier de démarrage à
chaud
Se reporter à la section
“REGLAGE DU LEVIER DE
DEMARRAGE A CHAUD” au
CHAPITRE 3.
14. Fixer le câble de démarrage à chaud
1 et le câble d’embrayage 2 à
l’aide d’un collier 3.
HANDLEBAR
GUIDON