3-58 ENGINE
FINAL SEAT CUT
• If the contact area is too low or too narrow, use the 45° cutter to
raise and widen the contact area.
NOTE:
After cutting the 15° angle, it is possible that the valve seat (45°)
is too narrow. If so, re-cut 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 previ-
ous 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 finish. This will
provide a soft surface for the final seating 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 valve clear-
ance after the cylinder head has been reinstalled. (
$
2-4)
Contact area too low and too
narrow on face of valve
15°
45°
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