D/valve train

D/VALVE TRAIN

Reconditioning

1. Renew the valve seats in the cylinder head using a valve seat cutter.

Note: Check guides for wear and if necessary, replace them before cutting the valve seats.

1. Seat width
2. 30 degrees
3. 45 degrees
4. 60 degrees

2. Carefully cut a 45 degree seat, removing only enough material to ensure a smooth and concentric seat.
3. Bevel the upper edge of the seat with the 30 degree cutter and the lower edge of the seat with the 60 degree cutter. Check width of seat and adjust accordingly.
4. Make one more very light pass with the 45 degree cutter to remove any possible burrs caused by the other cutter.

Valve Seat Width (Intake and exhaust):
Standard (New): 1.25 – 1.55mm
Service Limit: 2.00mm

1. Actual seating surface
2. Valve seat
3. Prussian blue compound

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 several times.
6. The actual valve seating surface, as shown by the blue compound, should be centred on the seat.

• If it is too high (closer to the valve stem), you must make a second cut with the 60 degree cutter to move it down, then one more cut with the 45 degree cutter to restore seat width.
• If it is too low (closer to the valve edge), you must make a second cut with the 30 degree cutter to move it up, then one more cut with the 45 degree cutter to restore seat width.

Note: The final cut should always be made with the 45 degree cutter.