2006 YAMAHA WR 250F engine oil

4 - 193
ENGAC MAGNETO AND STARTER CLUTCH
AC MAGNETO AND STARTER CLUTCH
Extent of removal:
1 Starter clutch/wheel gear removal
2 Rotor removal
3 Pickup coil/stator removal
Extent of removal Order Part name Q’ty Remarks
AC MAGNETO AND STATOR REMOVAL
Preparation for removal Drain the engine oil. Refer to “ENGINE OIL REPLACEMENT” section in
the CHAPTER 3.
Seat and fuel tank Refer to “SEAT, FUEL TANK AND SIDE COVERS”
section.
Bolt [radiator (left)] Refer to “RADIATOR” section.
Disconnect the AC magneto lead.
1 Shift pedal 1
2 Engine guard (left) 1
3 Cover (torque limiter) 1
4 Torque limiter 1 Do not disassemble.
5 Crankcase cover (left) 1
6 Gasket 1
7 Dowel pin 2
31

4 - 207
ENGAC MAGNETO AND STARTER CLUTCH
2. Install:
Holder
1
Bolt
2
CAUTION:
Pass the pickup coil lead and
charging coil lead under the
holder while taking care not to
allow these leads to get caught
with each other. Also take care to
pass the leads so that they do not
become loose at the bend of the
holder a
in order to avoid their
contacting the starter clutch drive
gear.
NOTE:Apply the sealant to the grommet of
the AC magneto lead.
T R..7 Nm (0.7 m · kg, 5.1 ft · lb)
YAMAHA Bond No. 1215
(ThreeBond® No. 1215):
90890-85505
12 a
3. Install:
Idle gear 2
1
Dowel pin
2
NOTE:Apply the engine oil on the idle gear
2.21
2
E
4. Install:
Idle gear plate
1
Bolt (idle gear plate)
2
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)
21
5. Install:
Washer
1
Bearing
2
Starter clutch drive gear
3
Washer 4
NOTE:Apply the engine oil on the washer,
bearing and starter clutch drive gear
inner circumference.
E12
3
4
2. Monter:
Support 1
Boulon 2
ATTENTION:
Passer le fil de la bobine d’excitation
et de la bobine de charge sous le sup-
port tout en veillant à ce que ces deux
fils ne puissent s’emmêler. Veiller éga-
lement à acheminer les fils de manière
qu’ils ne puissent se détendre au
niveau du coude du support a afin
qu’ils ne puissent pas entrer en con-
tact avec le pignon menant de
l’embrayage du démarreur.
N.B.:
Appliquer le produit d’étanchéité sur
l’oeillet caoutchouc du fil de l’alterna-
teur.
T R..7 Nm (0,7 m · kg, 5,1 ft · lb)
YAMAHA Bond N°1215
(ThreeBond® N°1215):
90890-85505
3. Monter:
Pignon fou 2 1
Goujon 2
N.B.:
Appliquer de l’huile moteur sur le
pignon fou 2.
4. Monter:
Plaque de pignon fou 1
Boulon (plaque de pignon fou) 2
T R..10 Nm (1,0 m · kg, 7,2 ft · lb)
5. Monter:
Rondelle 1
Roulement 2
Pignon menant de l’embrayage
de démarreur 3
Rondelle 4
N.B.:
Appliquer de l’huile moteur sur la ron-
delle, le roulement et la circonférence
intérieure du pignon menant de
l’embrayage du démarreur.
ALTERNATEUR AVEC ROTOR A ALIMENTATION PERMANENTE ET EMBRAYAGE DU DEMARREUR

4 - 211
ENGAC MAGNETO AND STARTER CLUTCH
9. Install:
Washer (rotor)
Nut (rotor)
1
Use the sheave holder
2.
NOTE:Tighten the rotor nut to 65 Nm
(6.5 mkg, 47 ftlb), loosen and
retighten the rotor nut to 65 Nm
(6.5 m  kg, 47 ft  lb).
T R..65 Nm (6.5 m · kg, 47 ft · lb)
Sheave holder:
YS-1880-A/
90890-01701
2
1
10. Install:
Dowel pin
Gasket [crankcase cover (left)]
Crankcase cover (left)
1
Bolt [crankcase cover (left)]
2
Bolt [crankcase cover (left)]
3
NOTE:Tighten the bolts in stage, using a
crisscross pattern.
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)
T R..12 Nm (1.2 m · kg, 8.7 ft · lb)
32
3
2
1New
11. Install:
Washer 1
Torque limiter 2
Washer 3
NOTE:Apply the engine oil to the shaft and
washers.
E
1
2
3
12. Install:
Cover (idle gear 1) 1
Bolt 2
NOTE:Install the cover (idle gear 1) with its
mark a facing upward.
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)
a
2
1
2
9. Monter:
Rondelle (rotor)
Ecrou (rotor) 1
Utiliser la clé à sangle 2.
N.B.:
Serrer l’écrou du rotor à 65 Nm
(6,5 mkg, 47 ftlb), desserrer puis
resserrer l’écrou du rotor à 65 Nm
(6,5 m kg, 47 ft  lb).
T R..65 Nm (6,5 m · kg, 47 ft · lb)
Clé à sangle:
YS-1880-A/90890-01701
10. Monter:
Goujon
Joint [couvercle de carter (gauche)]
Couvercle de carter (gauche) 1
Boulon
[couvercle de carter (gauche)] 2
Boulon
[couvercle de carter (gauche)] 3
N.B.:
Serrer les boulons par étapes et en procé-
dant en croix.
T R..10 Nm (1,0 m · kg, 7,2 ft · lb)
T R..12 Nm (1,2 m · kg, 8,7 ft · lb)
New
11. Monter:
Rondelle 1
Limiteur de couple 2
Rondelle 3
N.B.:
Appliquer de l’huile moteur sur l’arbre
et les rondelles.
12. Monter:
Couvercle (pignon fou 1) 1
Boulon 2
N.B.:
Monter le couvercle (pignon fou 1) en
orientant son repère a vers le haut.
T R..10 Nm (1,0 m · kg, 7,2 ft · lb)
ALTERNATEUR AVEC ROTOR A ALIMENTATION PERMANENTE ET EMBRAYAGE DU DEMARREUR

4 - 215
ENGENGINE REMOVAL
EC4M0000
ENGINE REMOVAL
Extent of removal Order Part name Q’ty Remarks
ENGINE REMOVAL
Preparation for removal Hold the machine by placing the suitable
stand under the frame.
WARNING
Support the machine securely so there is nodanger of it falling over.
Drain the engine oil. Refer to “ENGINE OIL REPLACEMENT” section in
the CHAPTER 3.
Seat and fuel tank Refer to “SEAT, FUEL TANK AND SIDE COVERS”
section.
Carburetor Refer to “CARBURETOR” section.
Exhaust pipe and silencer Refer to “EXHAUST PIPE AND SILENCER” section.
Air cut-off valve assembly Refer to “AIR INDUCTION SYSTEM” section.
Clutch cable Disconnect at the engine side.
Radiator Refer to “RADIATOR” section.
Shift pedal Refer to “AC MAGNETO AND STARTER CLUTCH”
section.
Cylinder head breather hose and oil tank
breather hoseRefer to “CAMSHAFTS” section.

4 - 219
ENGENGINE REMOVAL
Extent of removal:
1 Engine removal
Extent of removal Order Part name Q’ty Remarks
Ignition coil
Disconnect the AC magneto lead.
Starter motor lead Disconnect at the starter motor side.
Negative battery lead Disconnect at the engine side.
Right engine guard
1 Neutral switch 1
2 Drive chain sprocket cover 1
3 Nut (drive sprocket) 1
Refer to “REMOVAL POINTS”. 4 Lock washer 1
5 Drive sprocket 1
6 Clip 1
7 Bolt (brake pedal) 1
8 Brake pedal 1
9 Upper engine bracket 2
10 Lower engine bracket 2
11 Engine mounting bolt 3
12 Pivot shaft 1
Refer to “REMOVAL POINTS”.
13 Engine 1
1

4 - 227
ENGENGINE REMOVAL
2. Install:
Lock washer
1
Nut (drive sprocket)
2
NOTE:Tighten the nut while applying the
rear brake.
T R..75 Nm (7.5 m · kg, 54 ft · lb)
New
3. Bend the lock washer tab to lock
the nut.
4. Install:
Drive chain sprocket guide
1
Drive chain sprocket cover
2
Screw
(drive chain sprocket cover)
3
T R..8 Nm (0.8 m · kg, 5.8 ft · lb)
Oil hose and neutral switch
1. Install:
O-ring
1
Dowel pin
2
Oil hose
3
Bolt (oil hose)
4
NOTE:Apply the lithium soap base grease
on the O-ring.
T R..8 Nm (0.8 m · kg, 5.8 ft · lb)
New
2. Install:
Spring
1
Pin
2
O-ring
3
Neutral switch
4
Screw (neutral switch)
5
NOTE:Apply the lithium soap base grease
on the O-ring.
T R..4 Nm (0.4 m · kg, 2.9 ft · lb)
New
2. Monter:
Rondelle-frein 1
Ecrou (couronne arrière) 2
N.B.:
Serrer l’écrou tout en actionnant le frein
arrière.
T R..75 Nm (7,5 m · kg, 54 ft · lb)
New
3. Plier l’onglet de la rondelle-frein
pour bloquer l’écrou.
4. Monter:
Patin de chaîne de transmission
1
Couvercle de pignon de chaîne de
transmission 2
Vis (couvercle de pignon de
chaîne de transmission) 3
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.:
Appliquer de la graisse à savon de
lithium sur le joint torique.
T R..8 Nm (0,8 m · kg, 5,8 ft · lb)
T R..8 Nm (0,8 m · kg, 5,8 ft · lb)
New
2. Monter:
Ressort 1
Goupille 2
Joint torique 3
Contacteur de point mort 4
Vis (contacteur de point mort) 5
N.B.:
Appliquer de la graisse à savon de
lithium sur le joint torique.
T R..4 Nm (0,4 m · kg, 2,9 ft · lb)
New
DEPOSE DU MOTEUR

4 - 229
ENGCRANKCASE AND CRANKSHAFT
CRANKCASE AND CRANKSHAFT
Extent of removal:
1 Crankcase separation
2 Crankshaft removal
Extent of removal Order Part name Q’ty Remarks
CRANKCASE AND CRANKSHAFT
REMOVAL
Preparation for removal Engine Refer to “ENGINE REMOVAL” section.
Piston Refer to “CYLINDER AND PISTON” section.
Kick shaft assembly
Refer to “KICK SHAFT AND SHIFT SHAFT”
section.
Segment
Stator Refer to “AC MAGNETO AND STARTER CLUTCH”
section.
Balancer shaft Refer to “BALANCER” section.
1 Timing chain guide (intake side) 1
2 Timing chain 1
3 Oil delivery pipe 2 1
21

4 - 243
ENGCRANKCASE AND CRANKSHAFT
Crankshaft
1. Remove:
Crankshaft
1
Use the crankcase separating
tool
2.
CAUTION:
Do not use a hammer to drive out
the crankshaft.
Crankcase separating
tool:
YU-1135-A/
90890-01135
Crankcase bearing
1. Remove:
Bearing
1
NOTE:Remove the bearing from the
crankcase by pressing its inner
race.
Do not use the removed bearing.
INSPECTION
Timing chain and timing chain
guide
1. Inspect:
Timing chain
Cracks/stiff
→ Replace the
timing chain and camshaft
sprocket as a set.
2. Inspect:
Timing chain guide
Wear/damage
→ Replace.
Crankcase
1. Inspect:
Contacting surface
a
Scratches
→ Replace.
Engine mounting boss
b,
crankcase
Cracks/damage
→ Replace.
2. Inspect:
Bearing
Rotate inner race with a finger.
Rough spot/seizure
→
Replace.
3. Inspect:
Oil seal
Damage
→ Replace.
Vilebrequin
1. Déposer:
Vilebrequin 1
Utiliser l’outil de séparation de
carter moteur 2.
ATTENTION:
Ne pas chasser le vilebrequin au mar-
teau.
Outil de séparation de
carter moteur:
YU-1135-A/90890-01135
Roulement de carter
1. Déposer:
Roulement 1
N.B.:
Déposer le roulement en appuyant sur
sa cage externe.
Ne pas réutiliser le roulement déposé.
CONTROLE
Chaîne de distribution et patin de
chaîne de distribution
1. Contrôler:
Chaîne de distribution
Fissures/rigidité → Remplacer
ensemble la chaîne de distribu-
tion et le pignon d’arbre à cames.
2. Contrôler:
Patin de chaîne de distribution
Usure/endommagement → Rem-
placer.
Carter
1. Contrôler:
Surface de contact a
Rayures → Remplacer.
Noix de montage du moteur b,
carter
Craquelures/endommagement →
Remplacer.
2. Contrôler:
Roulement
Faire tourner la cage interne avec
le doigt.
Rugosité/grippage → Remplacer.
3. Contrôler:
Bague d’étanchéité
Endommagement → Remplacer.
CARTER MOTEUR ET VILEBREQUIN