Valve Clearance Inspection
Refer to Valve Clearance Inspection in the Periodic Maintanance
Valve Clearance Adjustment
Refer to Valve Clearance Adjustment in the Periodic Maintanance
Valve Seat Inspection
Remove the valve.
Check the valve seat surface [A] between the valve [B] and valve seat
Coat valve seat with machinists dye.
Push the valve into the guide.
Rotate the valve against the seat with a lapping tool.
Pull the valve out, and check the seating pattern on the valve head.
It must be the correct width and even all the way around.
Measure the outside diameter [D] of the seating pattern on the valve
If the outside diameter is too large or too small, repair the seat (see
Valve Seating Surface Outside Diameter
The valve stem and guide must be in good condition or this check
will not be valid.
If the valve seating pattern is not correct, repair the seat.
Measure the seat width [E] of the portion where there is no build-up
carbon (white portion) of the valve seat with a vernier caliper.
If the width is too wide [G], too narrow [H] or uneven [J], repair the
seat (see Seat Repair).
Valve Seat Width
ENGINE TOP END 4-21