2002 YAMAHA WR 426F transmission

ENG
4 - 95 CRANKCASE BEARING
Extent of removal:1 Crankcase bearing removal
Extent of removal Order Part name Q’ty Remarks
CRANKCASE BEARING
REMOVAL
Preparation for removal Transmission
Shift cam and shift forkRefer to “TRANSMISSION, SHIFT
CAM AND SHIFT FORK” section.
1 Oil seal 3
2 Bearing 10 Refer to “REMOVAL POINTS”.
1
CRANKCASE AND CRANKSHAFT

4 - 100
ENGCRANKCASE AND CRANKSHAFT
NOTE:
Hold the connecting rod at top dead center
with one hand while turning the nut of the
installing tool with the other. Operate the
installing tool until the crankshaft bottoms
against the bearing.
Before installing the crankshaft, clean the
contacting surface of crankcase.
CAUTION:
Do not use a hammer to drive in the crank-
shaft.
2. Check:
Shifter operation
Transmission operation
Unsmooth operation → Repair.
3. Install:
Oil strainer 1
Bolt (oil strainer) 2
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)
4. Apply:
Sealant
On the crankcase (right) 1.
NOTE:
Clean the contacting surface of crankcase (left
and right) before applying the sealant.
Quick gasket®:
ACC-QUICK-GS-KT
YAMAHA Bond No. 1215:
90890-85505

4 - 101
ENGCRANKCASE AND CRANKSHAFT
5. Install:
Dowel pin 1
O-ring 2
Crankcase (right)
To crankcase (left).
NOTE:
Fit the crankcase (right) onto the crankcase
(left). Tap lightly on the case with soft ham-
mer.
When installing the crankcase, the connect-
ing rod should be positioned at TDC (top
dead center).
6. Tighten:
Hose guide 1
Clutch cable holder 2
Bolt (crankcase)
NOTE:
Tighten the crankcase tightening bolts in
stage, using a crisscross pattern.
7. Install:
Oil delivery pipe
O-ring
Bolt (oil delivery pipe)
8. Install:
Timing chain
Timing chain guide (rear)
Bolt (timing chain guide)
9. Remove:
Sealant
Forced out on the cylinder mating sur-
face.
10. Apply:
Engine oil
To the crank pin, bearing and oil deliv-
ery hole.
11. Check:
Crankshaft and transmission operation.
Unsmooth operation → Repair.
New
T R..12 Nm (1.2 m · kg, 8.7 ft · lb)
New
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)

ENG
4 - 101
5. Montieren:
Paßstift 1
O-Ring 2
Kurbelgehäusehälfte
(rechts)
(auf die Kurbelgehäuse-
hälfte (links))
HINWEIS:
Die Kurbelgehäusehälfte (rechts)
auf die Kurbelgehäusehälfte (links)
montieren, Mit einem Gummiham-
mer leicht auf das Gehäuse klop-
fen.
Das Pleuel muß im oberen Tot-
punkt stehen.
6. Montieren:
Kabelführung 1
Kupplungszug-Halterung 2
Schraube (Kurbelgehäuse)
HINWEIS:
Die Kurbelgehäuse-Schrauben in
stufenweise und über Kreuz festzie-
hen.
7. Montieren:
Ölzufuhrleitung
O-Ring
Schraube (Ölzufuhrleitung)
8. Montieren:
Steuerkette
Steuerkettenschiene (hin-
ten)
Schraube (Steuerketten-
schiene)
9. Entfernen:
Dichtmittel
(von der Zylinderpaßfläche
getrieben)
10. Auftragen:
Motoröl
(auf Kurbelzapfen, Lager
und Ölzufuhrloch)
11. Kontrollieren:
Kurbelwelle und Getriebe
(Leichtgängigkeit)
Schwergängigkeit →
Instand setzen.
New
T R..12 Nm (1,2 m · kg)
New
T R..10 Nm (1,0 m · kg)
T R..10 Nm (1,0 m · kg)
5. Monter:
Goujon 1
Joint torique 2
Demi-carter (droit)
Vers le demi-carter (gauche).
N.B.:
Fixer le demi-carter (gauche) sur le
demi-carter (droit). Taper légèrement
sur le carter à l’aide d’un maillet.
Quand le carter est installé, la bielle
d’accouplement doit être positionnée
au PMH (point mort haut).
6. Monter:
Guide de flexible 1
Support de câble d’embrayage
2
Boulon (carter)
N.B.:
Serrer les boulons de serrage de carter
par étape en suivant un ordre entrecroisé.
7. Monter:
Tuyau d’arrivée d’huile
Joint torique
Boulon (tuyau d’arrivée
d’huile)
8. Monter:
Chaîne de distribution
Guide de chaîne de distribution
(arrière)
Boulon (guide de chaîne de
distribution)
9. Déposer:
Agent d’étanchéité
Sorti sur la surface usinée du
cylindre.
10. Appliquer:
Huile de moteur
Sur la goupille de carter, le rou-
lement et l’orifice de sortie
d’huile.
11. Contrôler:
Fonctionnement du vilebrequin
et de la transmission
Fonctionnement irrégulier →
Réparer.
New
T R..12 Nm (1,2 m · kg, 8,7 ft · lb)
New
T R..10 Nm (1,0 m · kg, 7,2 ft · lb)
T R..10 Nm (1,0 m · kg, 7,2 ft · lb)
5. Instalar:
Fijo de centraje 1
Junta tórica 2
Cárter (derecho)
Al cárter (izquierdo).
NOTA:
Coloque el cárter (derecho) en el cár-
ter (izquierdo). Golpéelos suavemente
con un martillo de plástico.
Cuando instale el cárter, la biela debe
estar colocada en el PMS (punto
muerto superior).
6. Apretar:
Guía del tubo 1
Soporte del cable del embrague
2
Perno (cárter)
NOTA:
Ajuste los pernos de apriete del cárter de
forma progresiva y entrecruzada.
7. Instalar:
Tubo de distribución aceite.
Junta tórica
Perno (rubo de distribución
aceite)
8. Instalar:
Cadena de transmisión
Guía de la cadena de transmi-
sión (trasera)
Perno (guía de la cadena de
distribución)
9. Extraer:
Un producto sellante
Ejerza fuerza sobre la superfi-
cie engranada del cilindro.
10. Aplicar:
Aceite de motor
Al bulón del cárter, al cojinete
y al orificio de distribución de
aceite.
11. Comprobar:
Funcionamiento del cigüeñal y
de la transmisión
Funcionamiento poco suave →
Reparar.
New
T R..12 Nm (1,2 m · kg, 8,7 ft · lb)
New
T R..10 Nm (1,0 m · kg, 7,2 ft · lb)
T R..10 Nm (1,0 m · kg, 7,2 ft · lb)
CARTER ET VILEBREQUIN
KURBELGEHÄUSE UND KURBELWELLE
CÁRTER Y CIGÜEÑAL

ENG
4 - 102
TRANSMISSION, SHIFT CAM AND SHIFT FORK
TRANSMISSION, SHIFT CAM AND SHIFT FORK
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 CRANK-
SHAFT” section.
1 Shift fork 1 1
Refer to “REMOVAL POINTS”. 2 Shift fork 2 1
3 Shift fork 3 1
4 Shift cam 1
5 Main axle 1
6 Drive axle 1
7Collar
1
1

4 - 103
ENGTRANSMISSION, SHIFT CAM AND SHIFT FORK
EC4H3000
REMOVAL POINTS
Shift fork, shaft cam and transmission
1. Remove:
Shift forks
Shift cam
Main axle
Drive axle
NOTE:
Tap lightly on the transmission drive axle and
shift cam with a soft hammer to remove.
Remove assembly carefully. Note the posi-
tion of each part. Pay particular attention to
the location and direction of shift forks.
EC4H4000
INSPECTION
EC4H4200
Gears
1. Inspect:
Matching dog a
Gear teeth b
Shift fork groove c
Wear/damage → Replace.
2. Inspect:
O-ring 1
Damage → Replace.
3. Check:
Gears movement
Unsmooth movement → Repair or
replace.
EC4H4600
Bearing
1. Inspect:
Bearing 1
Rotate inner race with a finger.
Rough spot/seizure → Replace.

4 - 104
ENGTRANSMISSION, SHIFT CAM AND SHIFT FORK
EC4H4801
Shift fork, shift cam and segment
1. Inspect:
Shift fork 1
Wear/damage/scratches → Replace.
2. Inspect:
Shift cam 1
Segment 2
Bend/wear/damage → Replace.
3. Check:
Shift fork movement
Unsmooth operation → Replace shift
fork.
NOTE:
For a malfunctioning shift fork, replace not only
the shift fork itself but the two gears each adja-
cent to the shift fork.
ASSEMBLY AND INSTALLATION
Transmission
1. Install:
5th pinion gear (25T) 1
3rd pinion gear (16T) 2
Collar 3
4th pinion gear (20T) 4
2nd pinion gear (15T) 5
To main axle 6.
NOTE:
Apply the molybdenum disulfide oil on the
4th and 5th pinion gears inner circumference
and on the end surface.
Apply the molybdenum disulfide oil on the
2nd and 3rd pinion gears inner circumfer-
ence.

4 - 105
ENGTRANSMISSION, SHIFT CAM AND SHIFT FORK
2. Install:
2nd wheel gear (26T) 1
4th wheel gear (21T) 2
3rd wheel gear (21T) 3
5th wheel gear (21T) 4
1st wheel gear (29T) 5
O-ring 6
To drive axle 7.
NOTE:
Apply the molybdenum disulfide oil on the
1st, 2nd and 3rd wheel gears inner circum-
ference and on the end surface.
Apply the molybdenum disulfide oil on the
4th and 5th wheel gears inner circumfer-
ence.
Apply the lithium soap base grease on the O-
ring.
3. Install:
Plain washer 1
Circlip 2
NOTE:
Be sure the circlip sharp-edged corner a is
positioned opposite side to the plain washer
and gear b.
Be sure the circlip end c is positioned at
axle spline groove d.
New
4. Install:
Collar 1
NOTE:
Apply the lithium soap base grease on the oil
seal lip.
When installing the spacer into the crank-
case, pay careful attention to the crankcase
oil seal lip.