Yamaha YZ450F, Owner'S Service Manual

Page: 288 / 650

4 - 24
ENG
CAMSHAFTS
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.
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