2007 YAMAHA YZ450F lock

4 - 29
ENG
With the rod fully wound and the chain ten-
sioner UP mark a facing upward, install
the gasket 1, the chain tensioner 2 and
the gasket 3, and tighten the bolt 4 to the
specified torque.
T R..
Bolt (timing chain tensioner):
10 Nm (1.0 m  kg, 7.2 ft  lb)
Release the screwdriver, check the ten-
sioner rod to come out and tighten the
gasket 5 and the cap bolt 6 to the speci-
fied torque.
T R..
Tensioner cap bolt:
7 Nm (0.7 m  kg, 5.1 ft  lb)
6
5New
3. Turn:
Crankshaft
Counterclockwise several turns
4. Check:
Rotor “I” mark
Align with the crankcase stationary
pointer.
Camshaft match marks
Align with the cylinder head surface.
Out of alignment → Adjust.
CAMSHAFTS

4 - 50
ENGCLUTCH
Extent of removal Order Part name Q’ty Remarks
12 Clutch plate 7
13 Friction plate 8
14 Nut 1
Use special tool.
Refer to “REMOVAL POINTS”. 15 Lock washer 1
16 Clutch boss 1
17 Thrust washer 1
18 Clutch housing 1
19 Push lever 1
4
1
3

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)