Yamaha F6AMH, Service Manual

Page: 280 / 510

CAMSHAFT AND VALVES
Refacing steps:
A
Valve seat is centered on valve face but
it is too wide.
B
Valve seat is in the middle of the valve
face but it is too narrow.
C
Valve seat is too narrow and it is near
the valve margin.
D
Valve seat is too narrow and it is near
the valve stem.
Valve cutter seat Desired result
Use
lightly
90° cutter
To reduce the valve
seat width
30° cutter
Valve cutter seat Desired result
Use 45° cutter
To increase the valve
seat width
Valve cutter seat Desired result
Use
90° cutter
To center the valve
seat and set it width
45° cutter
Valve cutter seat Desired result
Use
30° cutter
To center the valve
seat and set it width
45° cutter
A
B
C
D
5-50