Yamaha FX10X 2008 Service Manual page 220

VALVES AND VALVE SPRINGS
6. Measure:
• Valve stem runout
Out of specification → Replace the valve.
NOTE:
• When installing a new valve, always replace the
valve guide.
• If the valve is removed or replaced, always
replace the valve stem seal.
7. Eliminate:
• Carbon deposits
(from the valve face and valve seat)
8. Inspect:
• Valve seat
Pitting/wear → Replace the cylinder head.
9. Measure:
• Valve seat width a
Out of specification → Replace the cylinder
head.
Measurement steps:
• Apply Mechanic's blueing dye (Dykem) 1 onto
the valve face.
• Install the valve into the cylinder head.
• Press the valve through the valve guide and
onto the valve seat to make a clear impression.
• Measure the valve seat width.
NOTE:
Where the valve seat and valve face contacted one
another, the blueing will have been removed.
5-34
ENG
Valve stem runout:
0.010 mm (0.0004 in)
Valve seat width:
Intake:
0.90 ~ 1.10 mm
(0.0354 ~ 0.0433 in)
<Limit>: 1.6 mm (0.0630 in)
Exhaust:
0.90 ~ 1.10 mm
(0.0354 ~ 0.0433 in)
<Limit>: 1.6 mm (0.0630 in)