Valve Seat Inspection/Repair

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}
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.
  
  Fig 1: Checking Valve Seat Contact Width
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°

Fig 2: Checking Valve Seat Angle
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}

Fig 3: Measuring Protruding Length (Dimension L) Of Valve Stem