Valve Seat: Service and Repair
VALVE SEAT INSPECTION/REPAIR1. 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
0.99-1.84 mm (0.039-0.072 in)
2. Verify that the valve seating position is at the center of the valve face.
1) If the seating position is too inner side, correct the valve seat using a 70° (IN) or 65° (EX) cutter, and a 45° cutter.
2) If the seating position is too out side, correct the valve seat using a 30° (IN) or 0° (EX) cutter, and a 45° cutter.
Valve seat angle
45°
3. Inspect the sinking of the valve seat. Measure the protruding length (dimension L) of the valve stem.
^ If not specified, replace the valve.
^ If not as specified, replace the cylinder head.
Standard valve seat sinkage amount (Dimension L)
IN: 40.64-42.24 mm (1.601-1.662 in)
EX: 40.50-41.30 mm (1.60-1.65 in)