lock YAMAHA YZ450F 2007 Workshop Manual

4 - 51
ENGCLUTCH
EC493000
REMOVAL POINTS
EC483211
Clutch boss
1. Remove:
Nut 1
Lock washer 2
Clutch boss 3
NOTE:
Straighten the lock washer tab and use the
clutch holding tool 4 to hold the clutch boss.
ÈFor USA and CDN
ÉExcept for USA and CDN
Clutch holding tool:
YM-91042/90890-04086
È
É
EC494000
INSPECTION
EC484100
Clutch housing and boss
1. Inspect:
Clutch housing 1
Cracks/wear/damage → Replace.
Clutch boss 2
Scoring/wear/damage → Replace.
EC484201
Primary driven gear
1. Check:
Circumferential play
Free play exists → Replace.
Gear teeth
a
Wear/damage → Replace.
EC484400
Clutch spring
1. Measure:
Clutch spring free length
a
Out of specification → Replace springs
as a set.
Clutch spring free length:
Standard
50.0 mm (1.97 in) 49.0 mm (1.93 in)

4 - 53
ENGCLUTCH
EC4A5000
ASSEMBLY AND INSTALLATION
Push lever
1. Install:
Push lever 1
NOTE:
Apply the lithium soap base grease on the oil
seal lip.
Apply the engine oil on the push lever.
Clutch
1. Install:
Primary driven gear 1
Thrust washer 2
Clutch boss 3
NOTE:
Apply the engine oil on the primary driven gear
inner circumference.
2. Install:
Lock washer 1
Nut (clutch boss) 2
NOTE:
Install the lock washer with its concaves fit-
ted over the convexes of the clutch boss.
Use the clutch holding tool 3 to hold the
clutch boss.
ÈFor USA and CDN
ÉExcept for USA and CDN
Clutch holding tool:
YM-91042/90890-04086
New
T R..75 Nm (7.5 m · kg, 54 ft · lb)
ÈÉ
3. Bend the lock washer 1 tab.

4 - 63
ENGBALANCER
BALANCER
BALANCER
Extent of removal:
1 Balancer drive gear
2 Balancer
Extent of removal Order Part name Q’ty Remarks
BALANCER REMOVAL
Preparation for removal Clutch housing Refer to “CLUTCH” section.
Crankcase cover (right) Refer to “OIL FILTER, WATER PUMP AND
CRANKCASE COVER (RIGHT)” section.
Stator Refer to “CDI MAGNETO” section.
1 Nut (balancer) 1
Refer to “REMOVAL POINTS”. 2 Nut (primary drive gear) 1
3 Nut (balancer driven gear) 1
4 Lock washer 1
5 Balancer 1
6 Straight key 1
7 Conical washer 1
8 Primary drive gear 1
9 Balancer drive gear 1
10 Lock washer 1
11 Balancer driven gear 1
2
1
2
1

4 - 64
ENGBALANCER
REMOVAL POINTS
Balancer, balancer drive gear and balancer
driven gear
1. Straighten the lock washer tab.
2. Loosen:
Nut (balancer) 1
Nut (primary drive gear) 2
Nut (balancer driven gear) 3
NOTE:
Place an aluminum plate a between the teeth
of the balancer drive gear 4 and balancer
driven gear 5.
INSPECTION
Primary drive gear, balancer drive gear and
balancer driven gear
1. Inspect:
Primary drive gear 1
Balancer drive gear 2
Balancer driven gear 3
Wear/damage → Replace.
Balancer
1. Inspect:
Balancer
Cracks/damage → Replace.

4 - 64
ENG
DEMONTAGE-EINZELHEITEN
Ausgleichsvorrichtung, -Antriebsritzel und
-rad
1. Die Lasche der Sicherungsscheibe umbie-
gen.
2. Lockern:
Ausgleichswellen-Mutter 1
Mutter (Primärantriebsritzel) 2
Mutter (Ausgleichswellen-Antriebsrad) 3
HINWEIS:
Ein Alu-Blechstück a zwischen das Antriebs-
ritzel 4 und das Antriebsrad 5 der Aus-
gleichswelle klemmen.
KONTROLLE
Primärantriebsritzel, Ausgleichswellen-
Antriebsritzel und -rad
1. Kontrollieren:
Primärantriebsritzel 1
Ausgleichswellen-Antriebsritzel 2
Ausgleichswellen-Antriebsrad 3
Verschlissen/beschädigt → Erneuern.
Ausgleichswelle
1. Kontrollieren:
Ausgleichswelle
Rissig/beschädigt → Erneuern.
BALANCIER
AUSGLEICHSWELLE
POINTS DE DEPOSE
Balancier, pignon menant et pignon mené du
balancier
1. Redresser l’onglet de la rondelle-frein.
2. Desserrer:
Ecrou (balancier) 1
Ecrou (pignon menant de transmission pri-
maire) 2
Ecrou (pignon mené du balancier) 3
N.B.:
Placer une plaque d’aluminium a entre les dents
du pignon menant 4 et du pignon mené 5 du
balancier.
CONTROLE
Pignon menant de transmission primaire,
pignon menant et pignon mené du balancier
1. Contrôler:
Pignon menant de transmission primaire 1
Pignon menant du balancier 2
Pignon mené du balancier 3
Usure/endommagement → Remplacer.
Balancier
1. Contrôler:
Balancier
Craquelures/endommagement → Remplacer.

4 - 65
ENGBALANCER
ASSEMBLY AND INSTALLATION
Balancer, balancer drive gear and balancer
driven gear
1. Install:
Balancer driven gear 1
NOTE:
Install the balancer driven gear and balancer
shaft with their lower splines a aligning with
each other.
2. Install:
Balancer drive gear 1
NOTE:
Align the punched mark a on the balancer
drive gear with the punched mark b on the
balancer driven gear.
Install the balancer driven gear and crank-
shaft with the lower splines c aligning with
each other.
3. Install:
Lock washer 1
Nut (balancer driven gear) 2
Primary drive gear 3
Conical washer 4
Nut (primary drive gear) 5
Straight key 6
Balancer 7
Lock washer 8
Nut (balancer) 9
NOTE:
Apply engine oil to the contact surface and
threaded portion of the nut (primary drive
gear).
Place an aluminum plate a between the
teeth of the balancer drive gear 0 and bal-
ancer driven gear A.
Install the primary drive gear with its weight
reduction holes b facing the engine.
Install the conical washer with its convex sur-
face c outward.
4. Bend the lock washer tab.
a 0
1A
2
T R..50 Nm (5.0 m · kg, 36 ft · lb)
E
A
0a
c b
5
4
3
T R..110 Nm (11.0 m · kg, 80 ft · lb)
T R..45 Nm (4.5 m · kg, 33 ft · lb)

4 - 72
ENGKICK AXLE AND SHIFT SHAFT
REMOVAL POINTS
EC4B3101
Kick axle assembly
1. Remove:
Kick axle 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.
CAUTION:
If the segment gets an impact, it may be
damaged. Take care not to give an impact
to the segment when removing the bolt.
INSPECTION
EC4C4200
Kick axle and ratchet wheel
1. Check:
Ratchet wheel 1 smooth movement
Unsmooth movement → Replace.
Kick axle 2
Wear/damage → Replace.
Spring 3
Broken → Replace.

4 - 72
ENG
DEMONTAGE-EINZELHEITEN
Kickhebelwelle komplett
1. Demontieren:
Kickhebelwelle komplett 1
HINWEIS:
Die Torsionsfeder 2 aus der Bohrung a im
Kurbelgehäuse lösen.
Schaltführung und Schaltklinke
1. Demontieren:
Schaltführungs-Schraube
Schaltführung 1
Schaltklinke komplett 2
HINWEIS:
Schaltklinke und Schaltführung werden
gemeinsam zerlegt.
Stiftplatte
1. Demontieren:
Stiftplatten-Schraube 1
Stiftplatte 2
HINWEIS:
Die Stiftplatte bis zum Anschlag im Gegenuhr-
zeigersinn drehen und die Schraube lockern.
ACHTUNG:
Das Zahnsegment kann durch einen Stoß
beschädigt werden. Beim Demontieren der
Schraube darauf achten, das Zahnsegment
vor Stößen zu schützen.
KONTROLLE
Kickhebelwelle und Klinkenrad
1. Kontrollieren:
Leichtgängigkeit des Klinkenrads 1
Stockend → Erneuern.
Kickhebelwelle 2
Verschlissen/beschädigt → Erneuern.
Feder 3
Gebrochen → Erneuern.
ARBRE DE KICK ET AXE DE SELECTEUR
KICKHEBELWELLE UND SCHALTWELLE
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 sélecteur 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.
ATTENTION:
Si le segment reçoit un impact, il risque d’être
endommagé. Veiller à ne pas heurter le segment
lors de la dépose du boulon.
CONTROLE
Arbre de kick et roue à rochet
1. Contrôler:
Mouvement libre de la roue à rochet 1
Mouvement irrégulier → Remplacer.
Arbre de kick 2
Usure/endommagement → Remplacer.
Ressort 3
Cassé → Remplacer.

4 - 77
ENG
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
Plain washer 2
Circlip 3
NOTE:
Install the kick idle gear with its depressed
side a toward you.
Apply the engine oil on the kick idle gear
inner circumference.
New
KICK AXLE AND SHIFT SHAFT

4 - 82
ENGENGINE REMOVAL
Extent of removal:
1 Engine removal
Extent of removal Order Part name Q’ty Remarks
1 Neutral switch 1
2 Chain cover 1
3 Nut (drive sprocket) 1
Refer to “REMOVAL POINTS”. 4 Lock washer 1
5 Drive sprocket 1
6Clip 1
7 Bolt (brake pedal) 1
8 Brake pedal 1
9 Engine upper bracket (right) 1
10 Engine upper bracket (left) 1
11 Engine lower bracket 2
12 Engine mounting bolt 3
13 Pivot shaft 1
Refer to “REMOVAL POINTS”.
14 Engine 1
1