Valve Seat Inspection/Repair

VALVE SEAT INSPECTION/REPAIR
1. Measure the contact width of the valve face and the valve seat using the valve lapping compound.





- If it is not within the specification, resurface the valve seat using the 45° valve seat cutter.

Standard valve seat contact width
IN: 0.7-1.3 mm (0.0276-0.0511 in)
EX: 0.7-1.3 mm (0.0276-0.0511 in)

2. Verify that the area where the valve seat contacts the valve face is centered.
- If the seating position is too high, resurface the valve seat using a 70° (IN) 65° (EX) valve seat cutter and a 45° valve seat cutter.





- If the seating position is too low, resurface the valve seat using a 35° (IN) 30° (EX) valve seat cutter and a 45° valve seat cutter.

Valve seat angle
IN: 45°
EX: 45°

3. Inspect the valve seat for sinkage. Measure the protruding length (dimension L) of the valve stem using a valve of standard length.





- If it is not within the specification, replace the cylinder head.

Standard valve seat sinkage amount (Dimension L)
IN: 40.64-42.24 mm (1.600-1.662 in)
EX: 40.50-42.10 mm (1.595-1.657 in)