Mercury 4 SERIES

CYLINDER HEAD
90-857138R1 MAY 2000 Page 4A-17
VALVE SEAT POSITIONS AND CORRECTIONS
Condition: The valve seat is centered on valve face but it is too wide.
55799
Valve Seat Cutter Set Desired Results
Use
15° Cutter
To reduce valve seat
Use
Lightly
60° Cutter
To
reduce
valve
seat
width
Condition: The valve seat is in the middle of the valve face but it is too narrow.
55800
Valve Seat Cutter Set Desired Results
Use
45° Cutter
To achieve a uniform valve seat
Use
To
achieve
a
uniform
valve
seat
width
Condition: Valve seat is too narrow and it is near valve margin.
55801
Valve Seat Cutter Set Desired Results
Use
15° Cutter, First
To center the seat and to achieve its
Use
45° Cutter
To
center
the
seat
and
to
achieve
its
width