Checking The Valve Seats - Yamaha YP250R 2005 Service Manual

VALVES AND VALVE SPRINGS
5. Measure:
6. Measure:
NOTE:
• When installing a new valve, always replace
• If the valve is removed or replaced, always
EAS00240

CHECKING THE VALVE SEATS

The following procedure applies to all of the
valves and valve seats.
1. Eliminate:
5 - 23
• valve margin thickness a
Out of specification → Replace the valve.
Valve margin thickness
Intake
0.80 ~ 1.20 mm
(0.0315 ~ 0.0472 in)
<Limit> 0.5 mm (0.02 in)
Exhaust
0.80 ~ 1.20 mm
(0.0315 ~ 0.0472 in)
<Limit> 0.5 mm (0.02 in)
• valve stem runout
Out of specification → Replace the valve.
the valve guide.
replace the oil seal.
Valve stem runout
0.010 mm (0.0004 in)
• carbon deposits
(from the valve face and valve seat)
ENG