Checking The Valve Seats - Yamaha XV16AL Service Manual

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 oil seal.
EAS00240

CHECKING THE VALVE SEATS

The following procedure applies to all of
the valves and valve seats.
1. Eliminate:
• carbon deposits
(from the valve face and valve seat)
2. Check:
• valve seat
Pitting/wear → Replace the cylinder
head.
3. Measure:
• valve seat width a
Out of specification → Replace the cylin-
der head.
▼ ▼ ▼ ▼ ▼ ▼ ▼ ▼ ▼ ▼ ▼ ▼ ▼ ▼ ▼ ▼ ▼ ▼ ▼ ▼ ▼ ▼ ▼ ▼ ▼ ▼ ▼ ▼
a. Apply Mechanic's blueing dye (Dykem)
b onto the valve face.
b. Install the valve into the cylinder head.
c. Press the valve through the valve guide
and onto the valve seat to make a clear
impression.
5 - 48
ENG
Valve stem runout
0.01 mm (0.0004 in)
Valve seat width
Intake: 0.9 ~ 1.1 mm
(0.035 ~ 0.043 in)
<Limit>: 2.0 mm (0.079 in)
Exhaust: 0.9 ~ 1.1 mm
(0.035 ~ 0.043 in)
<Limit>: 2.0 mm (0.079 in)
5