Yamaha YZF-R7 Owner's Service Manual page 158

VALVES AND VALVE SPRINGS
5. Measure:
6. Measure:
EB403410
CHECKING THE VALVE SEATS
The following procedure applies to all of
the valves and valve seats.
1. Eliminate:
2. Check:
3. Measure:
4 - 26
• valve margin thickness a
Out of specification
valve.
Valve margin thickness
Intake
0.9 ~ 1.2 mm
(0.028 ~ 0.047 in)
Exhaust
1.0 ~ 1.3 mm
(0.039 ~ 0.051 in)
• valve stem runout
Out of specification
valve.
NOTE:
• When installing a new valve, always
replace the valve guide.
• If the valve is removed or replaced,
always replace the oil seal.
Valve stem runout
0.01 mm (0.0004 in)
• carbon deposits
(from the valve face and valve seat)
• valve seat
Pitting/wear Replace the cylinder
head.
• valve seat width a
Out of specification
inder head.
Valve seat width
0.9 ~ 1.1 mm
(0.035 ~ 0.043 in)
<Limit>: 1.6 mm (0.06 in)
ENG
Replace the
Replace the
Replace the cyl-