lock YAMAHA WR 450F 2007 Service Manual

4 - 26
ENGCAMSHAFTS
REMOVAL POINTS
Camshaft
1. Remove:
Timing plug 1
Straight plug 2
2. Align:
“I” mark
With stationary pointer.
Checking steps:
Turn the crankshaft counterclockwise with
a wrench.
Align the “I” mark a on the rotor with the
stationary pointer b on the crankcase
cover. When the “I” mark is aligned with
the stationary pointer, the piston is at the
Top Dead Center (T.D.C.).
NOTE:
In order to be sure that the piston is at Top
Dead Center, the punch mark c on the
exhaust camshaft and the punch mark d
on the intake camshaft must align with the
cylinder head surface, as shown in the
illustration.
If there is no clearance, rotate the crank-
shaft counterclockwise one turn.
1
2
b
a
3. Loosen:
Tensioner cap bolt 1
4. Remove:
Timing chain tensioner 2
5. Remove:
Bolt (camshaft cap) 1
Camshaft caps 2
NOTE:
Remove the bolts (camshaft cap) in a criss-
cross pattern, working from the outside in.
CAUTION:
The bolts (camshaft cap) must be removed
evenly to prevent damage to the cylinder
head, camshafts or camshaft caps.
1
2
1
2

ENG
4 - 26
DEMONTAGE-EINZELHEITEN
Nockenwelle
1. Demontieren:
Rotor-Abdeckschraube
1
Kurbelwellen-Abdeck-
schraube
2
2. Ausrichten:
I-Markierung
(auf die Gegenmarkierung)
Arbeitsvorgang:
Die Kurbelwelle mit einem
Schraubenschlüssel im Gegen-
uhrzeigersinn drehen.
Die I-Markierung
a am Licht-
maschinenrotor auf die entspre-
chende Gegenmarkierung
b
am Kurbelgehäuse ausrichten.
Wenn die I-Markierung mit der
entsprechenden Gegenmarkie-
rung fluchtet, befindet sich der
Kolben im oberen Totpunkt
(OT).
HINWEIS:
Der Kolben befindet sich im
oberen Totpunkt, wenn die Kör-
nermarkierung
c am Auslass-
Nockenwellenrad und die Kör-
nermarkierung
d am Einlass-
Nokkenwellenrad, wie in der
Abbildung gezeigt, mit der
Zylinderkopf-Passfläche fluch-
ten.
Die Kurbelwelle gegebenen-
falls um eine Umdrehung im
Gegenuhrzeigersinn drehen.
3. Lockern:
Steuerkettenspanner-Ver-
schlussschraube
1
4. Demontieren:
Steuerkettenspanner
2
5. Demontieren:
Schraube (Nockenwellen-
Lagerdeckel)
1
Nockenwellen-Lagerdeckel
2
HINWEIS:
Die Schrauben des Nockenwellen-
Lagerdeckels müssen von außen
nach innen schrittweise über Kreuz
gelockert werden.
ACHTUNG:
Um Schäden an Zylinderkopf,
Nockenwellen und Nockenwellen-
Lagerdeckeln zu vermeiden, müs-
sen die Lagerdeckel-Schrauben
gleichmäßig gelöst werden. POINTS DE DEPOSE
Arbre à cames
1. Déposer:
Bouchon de calage 1
Clavette droite 2
2. Aligner:
Repère “I”
Avec index fixe.
Etapes du contrôle:
Tourner le vilebrequin dans le sens
inverse des aiguilles d’une montre
à l’aide d’une clé.
Aligner le repère “I” a du rotor
avec l’index fixe b du couvercle
de carter moteur. Lorsque le repère
“I” est aligné avec l’index fixe, le
piston est au Point Mort Haut
(P.M.H.).
N.B.:
Le piston est au point mort haut
lorsque le repère poinçonné c de
l’arbre à cames d’échappement et
le repère poinçonné d de l’arbre à
cames d’admission sont alignés
avec la surface de la culasse
comme le montre l’illustration.
S’il n’y a pas de jeu, faire tourner
le vilebrequin d’un tour dans le
sens inverse des aiguilles d’une
montre.
3. Desserrer:
Boulon-capuchon du tendeur 1
4. Déposer:
Tendeur de chaîne de distribu-
tion 2
5. Déposer:
Boulon (chapeau d’arbre à
cames) 1
Chapeaux d’arbres à cames 2
N.B.:
Déposer les boulons (chapeau d’arbre à
cames) en croix, en procédant de l’exté-
rieur vers l’intérieur.
ATTENTION:
Les boulons (chapeau d’arbre à
cames) doivent être déposés uniformé-
ment pour prévenir tout endommage-
ment de la culasse, des arbres à cames
ou des chapeaux d’arbres à cames.PUNTOS DE DESMONTAJE
Eje de levas
1. Extraer:
Tapa de la distribución 1
Tapón recto 2
2. Alinear:
Marca “I”
Con la marca estacionaria.
Procedimiento de comprobación:
Gire el cigüeñal en el sentido con-
trario al de las agujas del reloj con
una llave.
Alinee la marca “I” a del rotor
con la marca estacionaria b de la
tapa del cárter. Cuando la marca
“I” está alineada con la marca esta-
cionaria, el pistón se encuentra en
punto muerto superior (PMS).
NOTA:
Para estar seguro de que el pistón
se encuentra en el punto muerto
superior, la marca perforada c en
el eje de levas de escape y la marca
perforada d en el eje de levas de
admisión deben alinearse con la
superficie de la culata, como se
muestra en la ilustración.
Si no hay holgura, gire el cigüeñal
una vuelta en el sentido contrario
al de las agujas del reloj.
3. Aflojar:
Perno capuchino del tensor 1
4. Extraer:
Tensor de cadena de distribución
2
5. Extraer:
Tornillo (tapa del eje de levas) 1
Tapas del eje de levas 2
NOTA:
Extraiga los tornillos (tapa del eje de
levas) en cruz, de fuera adentro.
ATENCION:
Los tornillos (tapa del eje de levas) se
deben extraer uniformemente para no
dañar la culata, los ejes de levas o las
tapas de estos.
ARBRES A CAMES
NOCKENWELLEN
EJES DE LEVAS

4 - 29
ENGCAMSHAFTS
Decompression system
1. Check:
Decompression system
Checking steps:
Check that the decompressor cam 1
moves smoothly.
Check that the decompressor lever pin 2
projects from the camshaft.
Timing chain tensioner
1. Check:
While pressing the tensioner rod lightly
with fingers, use a thin screwdriver 1
and wind the tensioner rod up fully clock-
wise.
When releasing the screwdriver by press-
ing lightly with fingers, make sure that the
tensioner rod will come out smoothly.
If not, replace the tensioner assembly.
ASSEMBLY AND INSTALLATION
1. Install:
Exhaust camshaft 1
Intake camshaft 2
Installation steps:
Turn the crankshaft counterclockwise until
the “I” mark a on the rotor is aligned with
the stationary pointer b on the crankcase
cover.
NOTE:
Apply the molybdenum disulfide oil on the
camshafts.
Apply the engine oil on the decompression
system.

4 - 30
ENGCAMSHAFTS
Fit the timing chain 3 onto both camshaft
sprockets and install the camshafts on the
cylinder head.
NOTE:
The camshafts should be installed onto the
cylinder head so that the exhaust cam
sprocket punch mark c and the intake cam
sprocket punch mark d align with the sur-
face of the cylinder head.
CAUTION:
Do not turn the crankshaft during the
camshaft installation. Damage or
improper valve timing will result.
Install the clips and camshaft caps 4.
T R..
Bolt (camshaft cap):
10 Nm (1.0 m  kg, 7.2 ft  lb)
NOTE:
Apply the molybdenum disulfide oil on the
thread of the bolts (camshaft cap) 5.
Tighten the bolts to the specified torque in
two or three steps in the proper tightening
sequence as shown.
CAUTION:
The bolts (camshaft cap) must be tight-
ened evenly, or damage to the cylinder
head, camshaft caps, and camshaft will
result.
2. Install:
Timing chain tensioner
Installation steps:
While pressing the tensioner rod lightly
with fingers, use a thin screwdriver and
wind the tensioner rod up fully clockwise.

4 - 31
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.
5. Install:
Timing plug 1
Straight plug 2
CAMSHAFTS

4 - 53
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
3
1
4

4 - 54
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
ÈÉ
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 - 56
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

4 - 57
ENGCLUTCH
3. Bend the lock washer 1 tab.
4. Install:
Friction plate 1
Clutch plate 1
[t = 2.0 mm (0.079 in)] 2
Clutch plate 2
[t = 1.6 mm (0.063 in)] 3
NOTE:
Install the clutch plates and friction plates
alternately on the clutch boss, starting with a
friction plate and ending with a friction plate.
Apply the engine oil on the friction plates and
clutch plates.
Check the clutch plate for thickness and
install 4 thicker ones a on the engine side
and 3 thinner ones b on the outside.
ab
5. Install:
Bearing 1
Plain washer 2
Circlip 3
To push rod 1 4.
NOTE:
Apply the engine oil on the bearing and plain
washer.
New
6. Install:
Push rod 2 1
Ball 2
Push rod 1 3
NOTE:
Apply the engine oil on the push rod 1, 2 and
ball.

4 - 66
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 “AC MAGNETO AND
STARTER CLUTCH” 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
2
1
2