Mercury 5 SERIES Service Manual page 125

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