Checking The Valve Seats - Yamaha FZ6-ST Supplementary Service Manual

VALVES AND VALVE SPRINGS
5. Measure:
S valve margin thickness a
Out of specification ! Replace the valve.
6. Measure:
S valve stem runout
Out of specification ! Replace the valve.
NOTE:
S When installing a new valve, always replace
the valve guide.
S If the valve is removed or replaced, always re-
place the oil seal.
EAS00240

CHECKING THE VALVE SEATS

The following procedure applies to all of the
valves and valve seats.
1. Eliminate:
S carbon deposits
(from the valve face and valve seat)
2. Check:
S valve seat
Pitting/wear ! Replace the cylinder head.
3. Measure:
S valve seat width a
Out of specification ! Replace the cylinder
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 impres-
sion.
d. Measure the valve seat width.
5-27
ENG
Valve margin thickness
0.6 X 0.8 mm
(0.0236 X 0.0315 in)
<Limit>: 0.5 mm (0.02 in)
Valve stem runout
<Limit>: 0.04 mm (0.0016 in)
Valve seat width
0.9 X 1.1 mm
(0.0354 X 0.0433 in)
<Limit>: 1.6 mm (0.06 in)