Suzuki AN650 2002 Service Manual page 83

3-32 ENGINE
BOTTOM NARROWING CUT
• If the contact area W is too wide or too low, use the 60° cutter
to narrow and raise the contact area.
FINAL SEAT CUT
• If the contact area W is too low or too narrow, use the 45° cut-
ter to raise and widen the contact area.
NOTE:
After cutting the 15°, 30° and 60° angles, it is possible that the
valve seat (45°) is too narrow. If so, recut the valve seat to the
correct width.
• After the desired seat position and width is achieved, use the
45° cutter very lightly to clean up any burrs caused by the pre-
vious cutting operations.
Do not use lapping compound after the final cut is
made. The finished valve seat should have a velvety
smooth finish but not a highly polished or shiny fin-
ish. This will provide a soft surface for the final seat-
ing of the valve which will occur during the first few
seconds of engine operation.
NOTE:
After servicing the valve seats, be sure to check the tappet
clearance after the cylinder head has been reinstalled. (
• Clean and assemble the head and valve components. Fill the
intake and exhaust ports with gasoline to check for leaks.
• If any leaks occur, inspect the valve seat and face for burrs or
other things that could prevent the valve from sealing.
Always use extreme caution when handling gasoline.
Too low or too narrow
contact surface on valve
2-9)
60˚
45˚