Engine; Adjusting The Valve Clearance - Yamaha YFZ450S 2003 Service Manual

ADJUSTING THE VALVE CLEARANCE

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4
2
1
1
2
EAS00048

ENGINE

ADJUSTING THE VALVE CLEARANCE
The following procedure applies to all of the
valves.
NOTE:
_
• Valve clearance adjustment should be made
on a cold engine, at room temperature.
• When the valve clearance is to be measured
or adjusted, the piston must be at the Top
Dead Center (TDC) on the compression
stroke.
1. Remove:
• seat
• fuel tank cover
• side covers (left and right)
• fuel tank
Refer to "SEAT, FENDERS AND FUEL
TANK".
2. Remove:
• ignition coil 1
• oil tank breather hose 2
• cylinder head breather hose 3
• spark plug
• cylinder head cover 4
3. Remove:
• timing mark accessing screw 1
• crankshaft end accessing screw 2
4. Measure:
• 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)
3 - 8
CHK
ADJ