lock YAMAHA WR 250F 2002 Service Manual

4 - 55
ENGCLUTCH
3. Bend the lock washer 1 tab.
4. Install:
Seat plate 1
Cushion spring 2
NOTE:
Install the seat plate with its chamfered por-
tion a facing the clutch boss 3.
Install the seat plate so that it is not caught
on the step b.
Install the cushion spring with the paint c
facing out.
1
2
c
3
a
b
5. Install:
Friction plate 1 1
Clutch plate 1 2
Friction plate 2 3
Clutch plate 2 4
NOTE:
Install the clutch plates and friction plates
alternately on the clutch boss, starting with a
friction plate and ending with a friction plate.
Use the friction plates 1 for the first and final
while paying attention to the difference in
surface pattern.
Apply the engine oil on the friction plates and
clutch plates.
Unlike 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.
6. Install:
Bearing 1
Washer 2
Circlip 3
To push rod 1 4.
NOTE:
Apply the engine oil on the bearing and
washer.

4 - 64
ENGBALANCER
BALANCER
Extent of removal:1 Balancer shaft drive gear2 Balancer shaft
Extent of removal Order Part name Q’ty Remarks
BALANCER REMOVAL
Preparation for removal Primary driven gear Refer to “CLUTCH” section.
Right crankcase cover Refer to “OIL FILTER ELEMENT,
WATER PUMP AND RIGHT CRANK-
CASE COVER” section.
Stator Refer to “CDI MAGNETO” section.
1 Nut (primary drive gear) 1
Refer to “REMOVAL POINTS”.
2 Nut (balancer shaft driven gear) 1
3 Lock washer 1
4 Primary drive gear 1
5 Balancer shaft drive gear 1
6 Lock washer 1
7 Balancer shaft driven gear 1
8 Balancer shaft 1 Refer to “REMOVAL POINTS”.
2
1
2

4 - 65
ENGBALANCER
REMOVAL POINTS
Balancer shaft drive gear and balancer
shaft driven gear
1. Straighten the lock washer tab.
2. Loosen:
Nut (primary drive gear) 1
Nut (balancer shaft driven gear) 2
NOTE:
Place an aluminum plate a between the teeth
of the balancer shaft drive gear 3 and driven
gear 4.
Balancer shaft
1. Remove:
Balancer shaft 1
NOTE:
When removing the balancer shaft, align the
center a of the balancer shaft weight along
the line connecting the centers of the crank-
shaft and balancer shaft.
INSPECTION
Primary drive gear, balancer shaft drive
gear and balancer shaft driven gear
1. Inspect:
Primary drive gear 1
Balancer shaft drive gear 2
Balancer shaft driven gear 3
Wear/damage → Replace.
Balancer shaft
1. Inspect:
Balancer shaft
Cracks/damage → Replace.

ENG
4 - 65
BALANCIER
AUSGLEICHSWELLE
BILANCIERE
AUSBAU
Ausgleichswellen-Antriebs- und -
Abtriebsräder
1. Die Lasche der Sicherungs-
scheibe umbiegen.
2. Lockern:
Mutter (Primärantriebsrad)
1
Mutter (Ausgleichswelle) 2
HINWEIS:
Ein Stückchen Aluminium a zwi-
schen die Zähne des Ausgleichswel-
len-Antriebsrades 3 und Aus-
gleichswellen-Abtriebrades 4 legen.
Ausgleichswelle
1. Demontieren:
Ausgleichswelle 1
HINWEIS:
Beim Ausbau der Ausgleichswelle
muß sich das Ausgleichsgewicht mit-
tig a auf der Fluchtlinie zwischen
den Mittelpunkten der Nockenwellen-
und Ausgleichswellen-Enden befin-
den.
PRÜFUNG
Primär- und Ausgleichswellen-
Antriebs- und -Abtriebsräder
1. Kontrollieren:
Primärantriebsrad 1
Ausgleichswellen-Antriebs-
rad 2
Ausgleichswellen-Abtriebs-
rad 3
Verschleiß/Beschädigung →
Erneuern.
Ausgleichswelle
1. Kontrollieren:
Ausgleichswelle
Rißbildung/Beschädigung
→ Erneuern. POINTS DE DEPOSE
Pignon menant et pignon mené du
balancier
1. Redresser l’ongle de rondelle
d’arrêt.
2. Desserrer:
Ecrou (pignon menant pri-
maire) 1
Ecrou (pignon mené de balan-
cier) 2
N.B.:
Placer une plaquette en aluminium a
entre les dents du pignon menant 3 et le
pignon mené 4 du balancier.
Balancier
1. Déposer:
Balancier 1
N.B.:
Avant de déposer l’arbre de balancier,
aligner le centre a du poids de l’arbre
de balancier avec la ligne reliant le cen-
tre du vilebrequin et le centre de l’arbre
de balancier.
CONTROLE
Pignon menant primaire, pignon
menant et pignon mené du balancier
1. Contrôler:
Pignon menant primaire 1
Pignon menant du balancier 2
Pignon mené du balancier 3
Usure/endommagements →
Remplacer.
Balancier
1. Contrôler:
Balancier
Craquelures/endommagement
→ Remplacer.PUNTI DI RIMOZIONE
Ingranaggio conduttore dell’albero di
equilibratura e ingranaggio condotto
dell’albero di equilibratura
1. Spianare la linguetta della ron-
della di bloccaggio.
2. Allentare:
Dado (ingranaggio conduttore
della trasmissione primaria) 1
Dado (Ingranaggio condotto
dell’albero di equilibratura) 2
NOTA:
Inserire una piastra di alluminio a tra i
denti dell’ingranaggio conduttore 3 e
l’ingranaggio condotto 4 dell’albero di
equilibratura.
Albero di equilibratura
1. Rimuovere:
Albero di equilibratura 1
NOTA:
Nel rimuovere l’albero di equilibratura,
allineare il centro del peso dell’albero di
equilibratura a lungo la linea che col-
lega i punti centrali dell’albero motore e
dell’albero di equilibratura.
ISPEZIONE
Ingranaggio conduttore della trasmis-
sione primaria, ingranaggio condut-
tore dell’albero di equilibratura e
ingranaggio condotto dell’albero di
equilibratura
1. Ispezionare:
Ingranaggio conduttore della
trasmissione primaria 1
Ingranaggio conduttore
dell’albero di equilibratura 2
Ingranaggio condotto
dell’albero di equilibratura 3
Usura/danno → Sostituire.
Albero di equilibratura
1. Ispezionare:
Albero di equilibratura
Incrinature/danno → Sostitu-
ire.

4 - 66
ENGBALANCER
ASSEMBLY AND INSTALLATION
Balancer shaft, balancer shaft drive gear
and balancer shaft driven gear
1. Install:
Balancer shaft 1
NOTE:
Apply the engine oil on the bearing.
When installing the balancer shaft, align the
center a of the balancer shaft weight along
the line connecting the centers of the crank-
shaft and balancer shaft.
2. Install:
Balancer shaft driven gear 1
NOTE:
Install the balancer shaft driven gear onto the
balancer shaft while aligning the punch mark
a on the balancer shaft driven gear with the
lower spline b on the balancer shaft end.
3. Install:
Balancer shaft drive gear 1
NOTE:
Align the punched mark a on the balancer
shaft drive gear with the punched mark b on
the balancer shaft driven gear 2.
Align the punched mark c on the balancer
shaft drive gear with the lower spline d on
the crankshaft end.
4. Install:
Lock washer 1
Nut (balancer shaft driven gear) 2
Primary drive gear 3
Nut (primary drive gear) 4
NOTE:
Install the primary drive gear with its stepped
side a facing the engine.
Place an aluminum plate b between the
teeth of the balancer shaft drive gear 5 and
driven gear 6.
5. Bend the lock washer tab.
T R..50 Nm (5.0 m · kg, 3.6 ft · lb)
T R..75 Nm (7.5 m · kg, 54 ft · lb)

4 - 74
ENGKICK SHAFT AND SHIFT SHAFT
REMOVAL POINTS
Kick shaft assembly
1. Remove:
Kick shaft assembly 1
NOTE:
Unhook the torsion spring 2 from the hole a
in the crankcase.
EC4C3101
Shift guide and shift lever assembly
1. Remove:
Bolt (shift guide)
Shift guide 1
Shift lever assembly 2
NOTE:
The shift lever assembly is disassembled at
the same time as the shift guide.
EC4N3100
Segment
1. Remove:
Bolt (segment) 1
Segment 2
NOTE:
Turn the segment counterclockwise until it
stops and loosen the bolt.
INSPECTION
Kick shaft and ratchet wheel
1. Check:
Ratchet wheel 1 smooth movement
Unsmooth movement → Replace.
Kick shaft 2
Wear/damage → Replace.
Spring 3
Broken → Replace.
EC4C4300
Kick gear, kick idle gear and ratchet wheel
1. Inspect:
Kick gear 1
Kick idle gear 2
Ratchet wheel 3
Gear teeth a
Ratchet teeth b
Wear/damage → Replace.

4 - 78
ENGKICK SHAFT AND SHIFT SHAFT
2. Install:
Torsion spring 1
To kick shaft 2.
NOTE:
Make sure the stopper a of the torsion spring
fits into the hole b on the kick shaft.
3. Install:
Spring guide 1
NOTE:
Slide the spring guide into the kick shaft, make
sure the groove a in the spring guide fits on
the stopper of the torsion spring.
4. Install:
Kick shaft assembly 1
Washer 2
NOTE:
Apply the molybdenum disulfide grease on
the contacting surfaces of the kick shaft stop-
per a and stopper plate 3.
Apply the engine oil on the kick shaft.
Slide the kick shaft assembly into the crank-
case and make sure the kick shaft stopper
fits into the stopper plate.
5. Hook:
Torsion spring 1
NOTE:
Turn the torsion spring clockwise and hook
into the proper hole a in the crankcase.
Kick idle gear
1. Install:
Kick idle gear 1
Washer 2
Circlip 3
NOTE:
Apply the engine oil on the kick idle gear
inner circumference.
Install the kick idle gear with its depressed
side a toward you.

4 - 84
ENGENGINE REMOVAL
Extent of removal:1 Engine removal
Extent of removal Order Part name Q’ty Remarks
Spark plug cap
Disconnect the CDI magneto lead.
Right engine guard
1 Neutral switch 1
2 Bolt (oil hose) 2
3 Drive chain sprocket cover 1
4 Nut (drive sprocket) 1
Refer to “REMOVAL POINTS”. 5 Lock washer 1
6 Drive sprocket 1
7 Clip 1
8 Bolt (brake pedal) 1
9 Brake pedal 1
10 Upper engine bracket 2
11 Lower engine bracket 2
12 Engine mounting bolt 3
13 Pivot shaft 1
Refer to “REMOVAL POINTS”.
14Engine
1
1

4 - 85
ENGENGINE REMOVAL
EC4M3000
REMOVAL POINTS
EC4F3100
Drive sprocket
1. Remove:
Nut (drive sprocket) 1
Lock washer 2
NOTE:
Straighten the lock washer tab.
Loosen the nut while applying the rear brake.
2. Remove:
Drive sprocket 1
Drive chain 2
NOTE:
Remove the drive sprocket together with the
drive chain.
EC4M3301
Engine removal
1. Remove:
Pivot shaft 1
NOTE:
If the pivot shaft is pulled all the way out, the
swingarm will come loose. If possible, insert a
shaft of similar diameter into the other side of
the swingarm to support it.
2. Remove:
Engine 1
From right side.
NOTE:
Make sure that the couplers, hoses and cables
are disconnected.

ENG
4 - 85
DEPOSE DU MOTEUR
MOTOR DEMONTIEREN
RIMOZIONE DEL MOTORE
AUSBAU
Antriebsritzel
1. Demontieren:
Mutter (Antriebsritzel) 1
Sicherungsscheibe 2
HINWEIS:
Die Lasche der Sicherungsscheibe
umbiegen.
Beim Lockern der Mutter die Hin-
terradbremse betätigen.
2. Demontieren:
Antriebsritzel 1
Antriebskette 2
HINWEIS:
Antriebsritzel und Antriebskette
gleichzeitig ausbauen.
Motor demontieren
1. Demontieren:
Schwingenachse 1
HINWEIS:
Durch Herausziehen der Schwingen-
achse wird die Schwinge gelöst. Um
dies zu vermeiden, eine Schraube
gleichen Durchmessers an der ande-
ren Seite einstecken.
2. Demontieren:
Motor 1
(von der rechten Seite)
HINWEIS:
Sicherstellen, daß zuvor alle Steck-
verbinder, Schläuche und Seilzüge
gelöst worden sind. POINTS DE DEPOSE
Pignon d’entraînement
1. Déposer:
Ecrou (pignon d’entraînement)
1
Rondelle-frein 2
N.B.:
Redresser la languette de la rondelle-
frein.
Desserrer l’écrou tout en actionnant le
frein arrière.
2. Déposer:
Pignon d’entraînement 1
Chaîne de transmission 2
N.B.:
Déposer le pignon d’entraînement avec
la chaîne de transmission.
Dépose du moteur
1. Déposer:
Axe de pivot 1
N.B.:
Si l’on sort complètement l’axe de pivot,
le bras oscillant va tomber. Si possible,
introduire une tige de diamètre équiva-
lent de l’autre côté du bras pour le soute-
nir.
2. Déposer:
Moteur 1
Du côté droit.
N.B.:
Vérifier que les fiches rapides, tuyaux et
câbles sont déconnectés.PUNTI DI RIMOZIONE
Corona dentata trasmissione
1. Rimuovere:
Dado (corona dentata trasmis-
sione) 1
Rondella di bloccaggio 2
NOTA:
Spianare la linguetta della rondella di
bloccaggio.
Svitare il dado agendo sul freno poste-
riore.
2. Rimuovere:
Corona dentata trasmissione 1
Catena di trasmissione 2
NOTA:
Rimuovere la corona dentata della tra-
smissione insieme alla catena di trasmis-
sione.
Rimozione del motore
1. Rimuovere:
Albero snodato 1
NOTA:
Se l’albero snodato viene spinto comple-
tamente fuori, il forcellone oscillante si
allenta. Se possibile, inserire un albero di
diametro simile nell’altro lato del forcel-
lone oscillante per sostenerlo.
2. Rimuovere:
Motore 1
Dal lato destro.
NOTA:
Accertarsi che gli accoppiatori, i flessi-
bili ed i cavi siano scollegati.