
3. Using a 45° cutter, remove enough material produce a smooth and concentric seat.
Turn the cutter clockwise, never counter-clockwise. Continue to turn the cutter as you
lift it from the valve seat.
[1]
CUTTER HOLDER: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 07781-0010101
[2]
SEAT CUTTER
HRD535/K1/K2
Valve seat cutter, 60° . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 07780-0014300
Valve seat cutter, 45° . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 07780-0011000
Valve seat cutter, 32° . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 07780-0012800
HRA536 - HRD536/K1/K2
Valve seat cutter, 60° . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 07780-0014000
Valve seat cutter, 45° . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 07780-0010200
Valve seat cutter, 32° . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 07780-0012100
[3]
CONTACT TOO HIGH
[4]
CONTACT TOO LOW
4. Use the 32° and 60° cutters to narrow and adjust the valve seat so that it contacts the
middle of the valve face. The 32° cutter removes material from the top edge. The 60°
cutter removes material from the bottom edge. Be sure that the width of the finished
valve seat is within specification.
Standard valve seat width
0.8 mm
5. Make a light pass with 45° cutter to remove any possible burs at the edges of the seat.
6. After resurfacing the seat, inspect for even valve seating. Apply Prussian Blue
compound or erasable felt-tippen marker ink to the valve faces. Insert the valves, and
then lift them and snap them closed against their seats several times. Be sure the
valve does not rotate on the seat.
The seating surface, as shown by the transferred marking compound, should have
good contact all the way around.
7. Lap the valves into their seats, using a hand lapper and lapping compound
(commercially available).
CAUTION:
•
To avoid severe engine damage, be sure to remove all lapping compound from the
engine before reassembly.
8. Check valve clearance after reassembly.
[5]
HAND VALVE LAPPING TOOL
- 71 -
HRA536 - HRD535 - HRD536
- CYLINDER HEAD / VALVES
[2]
[1]
S.TOOL
S.TOOL
[3]
[4]
0.8
mm
[5]
S.TOOL