SEAT WIDTH
2. Carefully grind a 45° seat, removing only enough
material to ensure a smooth and concentric seat.
3. Bevel the upper edge of the seat with the 30° stone
and the lower edge of the seat with the 60° stone.
Check width of seat and adjust accordingly.
4. Make one more very light pass with the 45° stone
to remove any possible burrs caused by the other
stones.
Valve Seat Width:
Standard: IN 0.80-1.00 mm (0.031-0.039 in)
EX 1.25-1.55 mm (0.049-0.061 in.)
Service Limit: IN 1.5 mm (0.059 in)
EX 2.0 mm (0.079 in)
1. Renew the valve seats in the cylinder head using a
valve seat grinder.
NOTE: If guides are worn (page 6-43), replace them
(page 6-44) before grinding the valve seats.
Valve Seats
Reconditioning
5. After resurfacing the seat, inspect for even valve
seating: Apply Prussian Blue compound to the valve
face, and insert valve in original location in the head,
then lift it and snap it closed against the seat sever-
al times.
ACTUAL
SEATING
SURFACE
VALVE
SEAT
PRUSSIAN BLUE COMPOUND
7. Insert intake and exhaust valves in the head and
measure valve stem installed height.
Valve Stem Installed Height (IN and EX):
Standard (New): 41.55-42.35 mm
(1.6358-1.6673 in)
Service Limit: 42.435 mm (1.6707 in)
VALVE STEM
INSTALLED HEIGHT
8. If valve stem installed height is over the service limit,
replace valve and recheck. If still over the service
limit, replace cylinder head; the valve seat in the head
is too deep.
6. The actual valve seating surface, as shown by the
blue compound, should be centered on the seat.
If it is too high (closer to the valve stem), you
must make a second cut with the 60° stone to
move it down, then one more cut with the 45°
stone to restore seat width.
If it is too low (closer to the valve edge), you must
make a second cut with the 30° stone to move
it up, then one more cut with the 45° stone to
restore seat width.
NOTE: The final cut should always be made with
the 45° stone.
2. Carefully grind a 45° seat, removing only enough
material to ensure a smooth and concentric seat.
3. Bevel the upper edge of the seat with the 30° stone
and the lower edge of the seat with the 60° stone.
Check width of seat and adjust accordingly.
4. Make one more very light pass with the 45° stone
to remove any possible burrs caused by the other
stones.
Valve Seat Width:
Standard: IN 0.80-1.00 mm (0.031-0.039 in)
EX 1.25-1.55 mm (0.049-0.061 in.)
Service Limit: IN 1.5 mm (0.059 in)
EX 2.0 mm (0.079 in)
1. Renew the valve seats in the cylinder head using a
valve seat grinder.
NOTE: If guides are worn (page 6-43), replace them
(page 6-44) before grinding the valve seats.
Valve Seats
Reconditioning
5. After resurfacing the seat, inspect for even valve
seating: Apply Prussian Blue compound to the valve
face, and insert valve in original location in the head,
then lift it and snap it closed against the seat sever-
al times.
ACTUAL
SEATING
SURFACE
VALVE
SEAT
PRUSSIAN BLUE COMPOUND
7. Insert intake and exhaust valves in the head and
measure valve stem installed height.
Valve Stem Installed Height (IN and EX):
Standard (New): 41.55-42.35 mm
(1.6358-1.6673 in)
Service Limit: 42.435 mm (1.6707 in)
VALVE STEM
INSTALLED HEIGHT
8. If valve stem installed height is over the service limit,
replace valve and recheck. If still over the service
limit, replace cylinder head; the valve seat in the head
is too deep.
6. The actual valve seating surface, as shown by the
blue compound, should be centered on the seat.
If it is too high (closer to the valve stem), you
must make a second cut with the 60° stone to
move it down, then one more cut with the 45°
stone to restore seat width.
If it is too low (closer to the valve edge), you must
make a second cut with the 30° stone to move
it up, then one more cut with the 45° stone to
restore seat width.
NOTE: The final cut should always be made with
the 45° stone.