Valve Clearance Adjustment - Yamaha YZ450F Fahrer- Und Wartungshandbuch

VALVE CLEARANCE ADJUSTMENT

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3. Remove:
• Timing plug 1
• Straight plug 2
• O-ring
4. Check:
• Valve clearance
Out of specification → Adjust.
Valve clearance (cold):
Intake valve:
0.10 ~ 0.15 mm
(0.0039 ~ 0.0059 in)
Exhaust valve:
0.20 ~ 0.25 mm
(0.0079 ~ 0.0098 in)
Checking steps:
• Turn the crankshaft counterclockwise with
a wrench.
• Align the T.D.C. mark a on the rotor with
the align mark b on the crankcase cover
when piston is at T.D.C. on compression
stroke.
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 cyl-
inder head surface, as shown in the illustra-
tion.
• Measure the valve clearance e using a
feeler gauge 1.
NOTE:
Record the measured reading if the clear-
ance is incorrect.
INSP
ADJ