2005 YAMAHA YZ250F lock

4 - 64
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 - 64
DEMONTAGE-EINZELHEITEN
Ausgleichswellen-Antriebsritzel
und -rad
1. Die Lasche der Sicherungs-
scheibe umbiegen.
2. Lockern:
Mutter (Primärantriebsritzel)
1
(Ausgleichswellen-Antriebs-
rad)
2
HINWEIS:
Ein Alu-Blechstück
a zwischen das
Antriebsritzel
3 und das Antriebs-
rad
4 klemmen.
Ausgleichswelle
1. Demontieren:
Ausgleichswelle
1
HINWEIS:
Zur Demontage der Ausgleichswelle
die Mitte
a des Ausgleichsgewichts
auf die Mitte der Ausgleichs- und
Kurbelwellen ausrichten.
KONTROLLE
Primärantriebsritzel, Ausgleichs-
wellen-Antriebsritzel und -rad
1. Kontrollieren:
Primärantriebsritzel
1
Ausgleichswellen-Antriebsrit-
zel
2
Ausgleichswellen-Antriebsrad
3
Verschlissen/beschädigt
→
Erneuern.
Ausgleichswelle
1. Kontrollieren:
Ausgleichswelle
Rissig/beschädigt
→ Erneu-
ern. POINTS DE DEPOSE
Pignon menant et pignon mené de
l’arbre de balancier
1. Redresser l’onglet de la rondelle-
frein.
2. Desserrer:
Ecrou (pignon menant de trans-
mission primaire) 1
Ecrou (pignon mené de l’arbre de
balancier) 2
N.B.:
Placer une plaque d’aluminium a entre
les dents du pignon menant de l’arbre de
balancier 3 et le pignon mené 4.
Arbre de balancier
1. Déposer:
Arbre de balancier 1
N.B.:
Pour déposer l’arbre de balancier, ali-
gner le centre a du contrepoids d’arbre
de balancier sur la ligne raccordant les
centres du vilebrequin et de l’arbre de
balancier.
CONTROLE
Pignon menant de transmission pri-
maire, pignon menant et pignon mené
de l’arbre de balancier
1. Contrôler:
Pignon menant de transmission
primaire 1
Pignon menant de l’arbre de
balancier 2
Pignon mené de l’arbre de balan-
cier 3
Usure/endommagement → Rem-
placer.
Arbre de balancier
1. Contrôler:
Arbre de balancier
Craquelures/endommagement →
Remplacer.PUNTI DI RIMOZIONE
Ingranaggi conduttore e condotto
dell’albero equilibratore
1. Spianare la linguetta della rondella
di bloccaggio.
2. Allentare:
Dado (ingranaggio conduttore
della trasmissione primaria) 1
Dado (ingranaggio condotto
dell’albero equilibratore) 2
NOTA:
Posizionare una piastra di alluminio a
tra i denti dell’ingranaggio conduttore
dell’albero equilibratore 3 e l’ingranag-
gio condotto 4.
Albero equilibratore
1. Togliere:
Albero equilibratore 1
NOTA:
Quando si rimuove l’albero equilibra-
tore, allineare il centro a del peso
dell’albero equilibratore lungo la linea
che collega i centri dell’albero motore e
dell’albero equilibratore.
CONTROLLO
Ingranaggio conduttore della trasmis-
sione primaria, ingranaggio condut-
tore dell’albero equilibratore e
ingranaggio condotto dell’albero equi-
libratore
1. Controllare:
Ingranaggio conduttore della tra-
smissione primaria 1
Ingranaggio conduttore
dell’albero equilibratore 2
Ingranaggio condotto dell’albero
equilibratore 3
Usura/danni → Sostituire.
Albero equilibratore
1. Controllare:
Albero equilibratore
Incrinature/danni → Sostituire.
BALANCIER
AUSGLEICHSWELLE
EQUILIBRATORE

4 - 65
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, 36 ft · lb)
T R..75 Nm (7.5 m · kg, 54 ft · lb)

4 - 73
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.

ENG
4 - 73
DEMONTAGE-EINZELHEITEN
Kickhebelwelle
1. Demontieren:
Kickhebelwelle
1
HINWEIS:
Die Torsionsfeder
2 aus der Boh-
rung
a im Kurbelgehäuse lösen.
Schaltführung und Schaltklinke
1. Demontieren:
Schaltführungs-Schraube
Schaltführung
1
Schaltklinke komplett
2
HINWEIS:
Schaltklinke und Schaltführung wer-
den gemeinsam zerlegt.
Stiftplatte
1. Demontieren:
Stiftplatten-Schraube
1
Stiftplatte
2
HINWEIS:
Die Stiftplatte bis zum Anschlag im
Gegenuhrzeigersinn drehen und die
Schraube lockern.
KONTROLLE
Kickhebelwelle und Klinkenrad
1. Kontrollieren:
Leichtgängigkeit des Klinken-
rads
1
Stockend
→ Erneuern.
Kickhebelwelle
2
Verschlissen/beschädigt
→
Erneuern.
Feder
3
Gebrochen
→ Erneuern.
Kickstarter-Ritzel, -Zwischenrad
und -Klinkenrad
1. Kontrollieren:
Kickstarter-Ritzel
1
Kickstarter-Zwischenrad
2
Klinkenrad
3
Verzahnung
a
Klinkenverzahnung
b
Verschlissen/beschädigt
→
Erneuern. POINTS DE DEPOSE
Arbre de kick complet
1. Déposer:
Arbre de kick complet 1
N.B.:
Décrocher le ressort de torsion 2 de
l’orifice a du carter.
Guide de sélecteur et levier de sélec-
teur complet
1. Déposer:
Boulon (guide de sélecteur)
Guide de sélecteur 1
Levier de sélecteur complet 2
N.B.:
Le levier de sélecteur complet se
démonte en même temps que le guide de
sélecteur.
Segment
1. Déposer:
Boulon (segment) 1
Segment 2
N.B.:
Tourner le segment dans le sens inverse
des aiguilles d’une montre jusqu’à la
butée et desserrer le boulon.
CONTROLE
Arbre de kick et roue à rochet
1. Contrôler:
Mouvement libre de la roue à
rochet 1
Mouvement irrégulier → Rem-
placer.
Arbre de kick 2
Usure/endommagement → Rem-
placer.
Ressort 3
Cassé → Remplacer.
Pignon de kick, pignon fou de kick et
roue à rochet
1. Contrôler:
Pignon de kick 1
Pignon fou de kick 2
Roue à rochet 3
Dents du pignon a
Dents du rochet b
Usure/endommagement → Rem-
placer.PUNTI DI RIMOZIONE
Gruppo albero pedale
1. Togliere:
Gruppo albero pedale 1
NOTA:
Sganciare la molla di torsione 2 dal
foro a nel carter.
Gruppo guida del cambio e leva del
cambio
1. Togliere:
Bullone (guida del cambio)
Guida del cambio 1
Gruppo leva del cambio 2
NOTA:
Il gruppo leva del cambio viene disas-
semblato contemporaneamente alla
guida del cambio.
Segmento
1. Togliere:
Bullone (segmento) 1
Segmento 2
NOTA:
Ruotare il segmento in senso antiorario
finché non si blocca, quindi allentare il
bullone.
CONTROLLO
Albero pedale e ruota con cricchetto
1. Controllare:
Movimento uniforme ruota con
cricchetto 1
Movimento non uniforme →
Sostituire.
Albero pedale 2
Usura/danni → Sostituire.
Molla 3
Rotto → Sostituire.
Ingranaggio pedale, ingranaggio folle
pedale e ruota con cricchetto
1. Controllare:
Ingranaggio pedale 1
Ingranaggio folle pedale 2
Ruota con cricchetto 3
Denti dell’ingranaggio a
Denti del cricchetto b
Usura/danni → Sostituire.
ARBRE DE KICK ET AXE DE SELECTEUR
KICKHEBELWELLE UND SCHALTWELLE
ALBERO PEDALE E ALBERO DEL CAMBIO

4 - 77
ENGKICK SHAFT AND SHIFT 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 kick shaft ratchet wheel guide 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 a
fits into the kick shaft ratchet wheel guide.
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 - 79
ENGCDI MAGNETO
EC4L3000
REMOVAL POINTS
Rotor
1. Remove:
Nut (rotor) 1
Washer 2
Use the rotor holding tool 3.
2. Remove:
Rotor 1
Use the flywheel puller 2.
NOTE:
When installing the flywheel puller, turn it
counterclockwise.
Rotor holding tool:
YU-1235/90890-01235
Flywheel puller:
YM-1189/90890-01189
EC4L4000
INSPECTION
EC4L4101
CDI magneto
1. Inspect:
Rotor inner surface a
Stator outer surface b
Damage → Inspect the crankshaft runout
and crankshaft bearing.
If necessary, replace CDI magneto and/
or stator.
EC4L4200
Woodruff key
1. Inspect:
Woodruff key 1
Damage → Replace.

4 - 83
ENGENGINE REMOVAL
Extent of removal:
1 Engine removal
Extent of removal Order Part name Q’ty Remarks
Ignition coil
Disconnect the CDI magneto lead.
Right engine guard
1 Lower engine guard 1
2 Neutral switch 1
3 Bolt (oil hose) 2
4 Drive chain sprocket cover 1
5 Nut (drive sprocket) 1
Refer to “REMOVAL POINTS”. 6 Lock washer 1
7 Drive sprocket 1
8Clip 1
9 Bolt (brake pedal) 1
10 Brake pedal 1
11 Upper engine bracket 2
12 Lower engine bracket 2
13 Engine mounting bolt 3
14 Pivot shaft 1
Refer to “REMOVAL POINTS”.
15 Engine 1
1