Mercury 40 FourStroke - Valve Refacing Steps

CYLINDER HEAD
Page 4A-36 90-857046R1 NOVEMBER 2001
Valve Refacing Steps
Condition: The valve seat is centered on valve face but it is too wide.
Valve Seat Cutter Set Desired Results
Use
Li htl
15° Cutter
To reduce valve seat
idth
Lightly
60° Cutter
width
Condition: The valve seat is in the middle of the valve face but it is too narrow.
Valve Seat Cutter Set Desired Results
Use 45° Cutter To achieve a uniform valve
t idth
seat width
Condition: Valve seat is too narrow and it is near valve margin.
Valve Seat Cutter Set Desired Results
Use
15° Cutter, First
To center the seat and to
hi it Width
45° Cutter
achieve its Width