2002 YAMAHA WR 250F oil

4 - 99
ENGTRANSMISSION, SHIFT CAM AND SHIFT FORK
EC4H4810
Shift fork, shift cam and segment
1. Inspect:
Shift fork 1
Wear/damage/scratches → Replace.
2. Inspect:
Shift cam 1
Segment 2
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.
EC4H5000
ASSEMBLY AND INSTALLATION
Transmission
1. Install:
5th pinion gear (27T) 1
3rd pinion gear (21T) 2
Collar 3
4th pinion gear (24T) 4
2nd pinion gear (16T) 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 - 100
ENGTRANSMISSION, SHIFT CAM AND SHIFT FORK
2. Install:
2nd wheel gear (28T) 1
4th wheel gear (25T) 2
3rd wheel gear (28T) 3
5th wheel gear (22T) 4
1st wheel gear (31T) 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:
Washer 1
Circlip 2
NOTE:
Be sure the circlip sharp-edged corner a is
positioned opposite side to the washer and
gear b.
Be sure the circlip end c is positioned at
axle spline groove d.
4. Install:
Collar 1
NOTE:
Apply the lithium soap base grease on the oil
seal lip.
When installing the collar into the crankcase,
pay careful attention to the crankcase oil seal
lip.

4 - 101
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 - 1
CHAS

EC500000
CHASSIS
EC590000
FRONT WHEEL AND REAR WHEEL
EC598000
FRONT WHEEL
FRONT WHEEL AND REAR 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
Preparation for removal
FRONT WHEEL REMOVAL
Hold the machine by placing the
suitable stand under the engine.
WARNING

Support the machine securely so there is no
danger of it falling over.
1 Trip meter cable 1
2 Brake hose cover 1
3 Bolt (brake hose holder) 2 Only loosening.
4 Bolt (axle holder) 4 Only loosening.
5 Nut (front wheel axle) 1
6 Front wheel axle 1
7 Front wheel 1
8 Trip meter gear unit 1
9 Collar 1
10 Oil seal 1
11 Bearing 2 Refer to “REMOVAL POINTS”.
12 Brake disc 1
2
31
3

5 - 2
CHAS

EC598100
REAR 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
Preparation for removal
REAR WHEEL REMOVAL
Hold the machine by placing the
suitable stand under the engine.
WARNING

Support the machine securely so there is no
danger of it falling over.
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”.
10Brake disc
1
2
31
3

FRONT WHEEL AND REAR WHEEL

5 - 3
CHAS

FRONT WHEEL AND REAR WHEEL
EC593000
REMOVAL POINTS
EC523101
Rear wheel
1. Remove:

Wheel
1

NOTE:

Push the wheel forward and remove the drive
chain
2
.
EC513201
Wheel bearing (if necessary)
1. Remove:

Bearing
1

NOTE:

Remove the bearing using a general bearing
puller
2
.
EC594000
INSPECTION
EC514100
Wheel
1. Measure:

Wheel runout
Out of limit
→
Repair/replace.
2. Inspect:

Bearing
Rotate inner race with a finger.
Rough spot/seizure
→
Replace.
NOTE:

Replace the bearings, oil seal and wheel collar
as a set.
Wheel runout limit:
Radial
1
: 2.0 mm (0.08 in)
Lateral
2
: 2.0 mm (0.08 in)

5 - 3
CHAS

ROUE AVANT ET ROUE ARRIERE
VORDER- UND HINTERRAD
RUOTA ANTERIORE E RUOTA POSTERIORE
AUSBAU
Hinterrad
1. Demontieren:

Rad
1

HINWEIS:

Das Rad nach vorne stoßen und die
Antriebskette
2
abnehmen.
Radlager (nach Bedarf)
1. Demontieren:

Lager
1

HINWEIS:

Die Lager mit einem Lageraustreiber
2
ausbauen.
PRÜFUNG
Rad
1. Messen:

Felgenschlag
Unvorschriftsmäßig
→

Instand setzen/Erneuern.
Max. Felgenschlag
Höhenschlag
1

2,0 mm
Seitenschlag
2

2,0 mm
2. Kontrollieren:

Lager
Den inneren Laufring mit
dem Finger drehen.
Schwergängigkeit/Freßspu-
ren
→
Erneuern.
HINWEIS:

Lager, Dichtringe und Hülse im Satz
erneuern.
POINTS DE DEPOSE
Roue arrière
1. Déposer:

Roue
1

N.B.:

Pousser la roue vers l’avant et déposer la
chaîne de transmission
2
.
Roulement de roue (si nécessaire)
1. Déposer:

Roulement
1
N.B.:
Déposer le roulement en utilisant un
arrache-roulement courant 2.
CONTROLE
Roue
1. Mesure:
Voile de roue
Hors limite → Réparer/rempla-
cer.
Limite de voile de la roue:
Radial 1: 2,0 mm
(0,08 in)
Latéral 2: 2,0 mm
(0,08 in)
2. Contrôler:
Roulement
Faire tourner la bague inté-
rieure avec le doigt.
Point dur/grippage → Rempla-
cer.
N.B.:
Changer à la fois les roulements, la
bague d’étanchéité et la collerette de
roue.PUNTI DI RIMOZIONE
Ruota posteriore
1. Rimuovere:
Ruota 1
NOTA:
Spingere la ruota in avanti e rimuovere
la catena di trasmissione 2.
Cuscinetto della ruota (se necessario)
1. Rimuovere:
Cuscinetto 1
NOTA:
Rimuovere il cuscinetto impiegando un
estrattore per cuscinetti 2.
ISPEZIONE
Ruota
1. Misurare:
Scentratura
Fuori limite → Riparare/sosti-
tuire.
Limite di disassamento
ruota:
Radiale 1: 2,0 mm
(0,08 in)
Laterale 2: 2,0 mm
(0,08 in)
2. Ispezionare:
Cuscinetto
Far ruotare l’anello interno con
un dito.
Punti rugosi/grippaggio →
Sostituire.
NOTA:
Sostituire in blocco i cuscinetti, il parao-
lio ed il collarino della ruota.

5 - 4
CHAS
ROUE AVANT ET ROUE ARRIERE
VORDER- UND HINTERRAD
RUOTA ANTERIORE E RUOTA POSTERIORE
Radachse
1. Messen:
Radachsschlag
Unvorschriftsmäßig →
Erneuern.
Die Meßuhr 1 verwenden.
HINWEIS:
Der Radachsschlag entspricht der
Hälfte der Meßuhranzeige.
WARNUNG
Nie versuchen, eine verbogene
Achse zu richten.
Max. Radachsschlag
0,5 mm
Bremsscheibe
1. Messen:
Bremsscheibenschlag (nur
Hinterrad-Bremsscheibe)
Die Meßuhr 1 verwenden.
Unvorschriftsmäßig → Fel-
genschlag prüfen.
Falls im Sollbereich, die
Bremsscheibe erneuern.
2. Messen:
Bremsscheibenstärke a
Unvorschriftsmäßig →
Erneuern.
Max. Bremsscheiben-
verzug
Hinten
0,15 mm
Bremsscheiben-Min-
deststärke
Vorn
3,0 mm
2,5 mm
Hinten
4,0 mm
3,5 mm
Axe de roue
1. Mesurer:
Déformation de l’axe de roue
Hors-spécification → Rempla-
cer.
Utiliser le comparateur 1.
N.B.:
La valeur de déformation est égale à la
moitié de la lecture du comparateur.
AVERTISSEMENT
Ne jamais tenter de redresser un axe
tordu.
Limite de déformation de
l’axe de roue:
0,5 mm (0,020 in)
Disque de frein
1. Mesurer:
Déflexion de disque de frein
(disque de frein arrière unique-
ment)
Utiliser le comparateur 1.
Hors spécification → Exami-
ner le voile de roue.
Si le voile de la roue est nor-
mal, changer le disque de frein.
2. Mesurer:
Epaisseur de disque de frein a
Hors limite → Remplacer.
Limite de déflexion de dis-
que:
Arrière:
:0,15 mm
(0,006 in)
Limite d’usure de disque:
Avant:
3,0 mm (0,12 in)
: 2,5 mm
(0,10 in)
Arrière:
4,0 mm (0,16 in)
: 3,5 mm
(0,14 in)
Asse della ruota
1. Misurare:
Deformazioni asse della ruota
Fuori specifica → Regolare.
Utilizzare un comparatore 1.
NOTA:
Il valore di deformazione corrisponde
alla metà del valore indicato dal compa-
ratore.
AVVERTENZA
Non tentare di raddrizzare un asse
deformato.
Limite di deformazione
dell’asse della ruota:
0,5 mm (0,020 in)
Disco freno
1. Misurare:
Deflessione disco del freno
(solo disco del freno poste-
riore)
Utilizzare un comparatore 1.
Fuori specifica → Ispezionare
il disassamento della ruota.
Se il disassamento è in buone
condizioni, sostituire il disco
del freno.
2. Misurare:
Spessore del disco del freno a
Fuori limite → Sostituire.
Limite di deflessione del
disco freno:
Posteriore:
: 0,15 mm
(0,006 in)
Spessore del disco freno:
Anteriore:
3,0 mm (0,12 in)
: 2,5 mm
(0,10 in)
Posteriore:
4,0 mm (0,16 in)
: 3,5 mm
(0,14 in)