Valve Seat Inspection

• Remove the valve (see Valve Removal).
• Check the valve seating surface [A] between the valve [B] and valve seat [C].

Measure the outside diameter [D] of the seating pattern on the valve seat.

If the outside diameter is too large or too small, repair the seat (see Valve Seat Repair).

Valve Seating Surface Outside Diameter Standard:

Exhaust 23.9 24.1 mm (0.941
0.949 in.)

Intake 30.4 30.6 mm (1.197
1.205 in.)

Measure the seat width [E] of the portion where there is no build-up carbon (white portion) of the valve seat with a vernier caliper.

Good [F]

If the width is too wide [G], too narrow [H] or uneven [J], repair the seat (see Valve Seat Repair).

Valve Seating Surface Width Standard:

Exhaust 0.8 1.2 mm (0.03
0.05 in.)

Intake 0.5 1.0 mm (0.02
0.04 in.)