1995 Mariner Mercury Outboards Service Manual 50HP 4-Stroke, Page 130Get this manual
Valve Seat Cutter Set
Desired Results
INSTALLING VALVES
15 Cutter, First 45 Cutter
To center the seat and to achieve its Width
Always use new valve sealsApply engine oil to the valves and valve seatsInstall valves as shown
Condition: Valve seat is to narrow and is located near the bottom edge of the valve faceValve Seat Cutter Set Desired Results
60 Cutter, First 45 Cutter