2001 YAMAHA WR 250F oil

4 - 47
ENGCYLINDER AND PISTON
2. Position:
lTop ring
l2nd ring
lOil ring
Offset the piston ring end gaps as
shown.
aTop ring end
b2nd ring end
cOil ring end (upper)
dOil ring
eOil ring end (lower)
3. Install:
lPiston 1
lPiston pin 2
lPiston pin clip 3
NOTE:
lApply engine oil onto the piston pin and pis-
ton.
lBe sure that the arrow mark a on the piston
points to the exhaust side of the engine.
lBefore installing the piston pin clip, cover the
crankcase with a clean rag to prevent the
piston pin clip from falling into the crankcase.
lInstall the piston pin clips with their ends fac-
ing downward.
45¡
135¡135¡
a
b ced
3New
Cylinder
1. Lubricate:
lPiston
lPiston ring
lCylinder
NOTE:
Apply a liberal coating of engine oil.
2. Install:
lDowel pin 1
lO-ring 2
NOTE:
Apply the lithium soap base grease on the O-
ring.

4 - 49
ENGCLUTCH
EC4A0000
CLUTCH
Extent of removal:1 Push rod 1, 2 and push lever shaft removal2 Push pod 1 disassembly
3 Friction plate and clutch plate removal4 Primary driven gear removal
Extent of removal Order Part name Q’ty Remarks
CLUTCH REMOVAL
Preparation for removal Drain the engine oil. Refer to “ENGINE OIL REPLACEMENT”
section in the CHAPTER 3.
Brake pedal Refer to “ENGINE REMOVAL” section.
Clutch cable Disconnect at engine side.
1 Clutch cover 1
2 Clutch spring 5
3 Pressure plate 1
4 Push rod 1 1
5 Circlip 1
6 Washer 1
7 Bearing 1
8 Ball 1
9Push rod 2
1
4
1
12
3

ENG
4 - 52
EMBRAYAGE
KUPPLUNG
FRIZIONE
Reibscheiben
1. Messen:
lReibscheibenstärke
Unvorschriftsmäßig ® Die
Reibscheiben im Satz
erneuern.
Die Reibscheiben an vier
Stellen messen.
Kupplungsscheiben
1. Messen:
lVerzug der Kupplungsschei-
ben
Unvorschriftsmäßig ®
Kupplungsscheiben im Satz
erneuern.
Eine Richtplatte 1 und eine
Fühlerlehre 2 verwenden.
Reibscheibenstärke
2,9–3,1 mm
2,7 mm
Verzugsgrenze
0,1 mm
Druckhebel
1. Kontrollieren:
lDruckhebelwelle 1
Verschleiß/Beschädigung ®
Erneuern.
Druckstangen
1. Kontrollieren:
lDruckstange 1 1
lLager 2
lUnterlegscheibe 3
lDruckstange 2 4
lKugel 5
Verschleiß/Beschädigung/
Verbiegung ® Erneuern. Disque de friction
1. Mesurer:
lEpaisseur de disque de friction
Hors-spécification ® Changer
tous les disques de friction.
Mesurer chaque disque en qua-
tre endroits.
Disque d’embrayage
1. Mesurer:
lVoile de disque d’embrayage
Hors spécification ® Rampla-
cer tous les disques
d’embrayage.
Utiliser une plaque à surfacer
1 et une jauge d’épaisseur 2.
Epaisseur de disque de
friction:
2,9 à 3,1 mm
(0,114 à 0,122 in)
: 2,7 mm
(0,106 in)
Limite de déformation:
0,1 mm (0,004 in)
Levier de poussée
1. Contrôler:
lArbre de levier de poussée 1
Usure/endommagement ®
Ramplacer.
Tige de poussée
1. Contrôler:
lTige de poussée 1 1
lRoulement 2
lRondelle 3
lTige de poussée 2 4
lBille 5
Usure/endommagement/défor-
mation ® Ramplacer.Disco conduttore
1. Misurare:
lSpessore del disco conduttore
Fuori specifica ® Sostituire in
blocco il disco conduttore.
Misurare tutti i quattro punti.
Disco condotto
1. Misurare:
lDeformazione del disco con-
dotto
Fuori specifica ® Sostituire in
blocco il disco condotto.
Utilizzare un piano di riscon-
tro 1 ed uno spessimetro 2.
Spessore del disco condut-
tore:
2,9 ~ 3,1 mm
(0,114 ~ 0,122 in)
: 2,7 mm
(0,106 in)
Limite di deformazione:
0,1 mm (0,004 in)
Alberino della leva spingente
1. Ispezionare:
lAlberino della leva spingente
1
Usura/danno ® Sostituire.
Asta di punteria
1. Ispezionare:
lAsta di punteria 1 1
lCuscinetto 2
lRondella 3
lAsta di punteria 2 4
lSfera 5
Usura/danno/flessioni ® Sosti-
tuire.

4 - 53
ENGCLUTCH
EC4A5000
ASSEMBLY AND INSTALLATION
Push lever shaft
1. Install:
lPush lever shaft 1
lBolt (push lever shaft) 2
NOTE:
lApply the lithium soap base grease on the oil
seal lip.
lApply the engine oil on the push lever shaft.
lFit the seat plate 3 in the groove a of the
push lever shaft and tighten the bolt (seat
plate).
3
1
a2
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)
Clutch
1. Install:
lPrimary driven gear 1
lThrust washer 2
lClutch boss 3
NOTE:
Apply the engine oil on the primary driven gear
inner circumference.
2. Install:
lLock washer 1
lNut (clutch boss) 2
NOTE:
Use the clutch holding tool 3 to hold the clutch
boss.
For USA and CDN
õExcept for USA and CDN
Clutch holding tool:
YM-91042/90890-04086
T R..60 Nm (6.0 m · kg, 43 ft · lb)

õ

4 - 54
ENGCLUTCH
3. Bend the lock washer 1 tab.
4. Install:
lSeat plate 1
lCushion spring 2
NOTE:
lInstall the seat plate with its chamfered por-
tion a facing the clutch boss 3.
lInstall the cushion spring with the paint b
facing out.
1
2 1
2 3
a
b
5. Install:
lFriction plate 1 1
lClutch plate 1 2
lFriction plate 2 3
lClutch plate 2 4
NOTE:
lInstall the clutch plates and friction plates
alternately on the clutch boss, starting with a
friction plate and ending with a friction plate.
lUse the friction plates 1 for the first and final
while paying attention to the difference in
surface pattern.
lApply the engine oil on the friction plates and
clutch plates.
lUnlike the clutch plate 2, the clutch plate 1
has no surface gloss. Use the clutch plate 1
for the first while paying attention to the dif-
ference in surface gloss.
1
2
6. Install:
lBearing 1
lWasher 2
lCirclip 3
To push rod 1 4.
NOTE:
Apply the engine oil on the bearing and
washer.

4 - 55
ENGCLUTCH
7. Install:
lPush rod 2 1
lBall 2
lPush rod 1 3
NOTE:
Apply the engine oil on the push rod 1, 2 and
ball.
8. Install:
lPressure plate 1
9. Install:
lClutch spring 1
lBolt (clutch spring) 2
NOTE:
Tighten the bolts in stage, using a crisscross
pattern.
T R..8 Nm (0.8 m · kg, 5.8 ft · lb)
10. Install:
lDowel pin 1
lGasket (clutch cover) 2
11. Install:
lClutch cover 1
lBolt (clutch cover)
NOTE:
Tighten the bolts in stage, using a crisscross
pattern.
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)

4 - 56
ENG
OIL FILTER ELEMENT, WATER PUMP AND RIGHT
CRANKCASE COVER
OIL FILTER ELEMENT, WATER PUMP AND RIGHT
CRANKCASE COVER
Extent of removal:1 Oil filter element removal2 Water pump removal
3 Right crankcase cover removal
Extent of removal Order Part name Q’ty Remarks
OIL FILTER ELEMENT, WATER
PUMP AND RIGHT CRANK-
CASE COVER REMOVAL
Preparation for removal Drain the engine oil. Refer to “ENGINE OIL REPLACEMENT”
section in the CHAPTER 3.
Drain the coolant. Refer to “COOLANT REPLACEMENT”
section in the CHAPTER 3.
Radiator hose 3 Disconnect at water pump side.
Exhaust pipe Refer to “EXHAUST PIPE AND
SILENCER” section.
Brake pedal Refer to “ENGINE REMOVAL” section.
Right engine guard
1 Oil filter element cover 1
2 Oil filter element 1
13

4 - 57
ENG
OIL FILTER ELEMENT, WATER PUMP AND RIGHT
CRANKCASE COVER
Extent of removal Order Part name Q’ty Remarks
3 Water pump housing 1
4 Oil delivery pipe 1
5 Bolt (oil hose) 1
6 Kickstarter crank 1
7 Right crankcase cover 1
8 Impeller 1
Refer to “REMOVAL POINTS”. 9 Washer 1
10 Impeller shaft 1
11 Oil seal 2
12Bearing
1
3
2