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
Exhaust 23.5 ∼ 23.7 mm (0.925 ∼ 0.933 in.)
29.3 ∼ 29.5 mm (1.15 ∼ 1.16 in.)
Measure the seat width [E] of the portion where there is
no build-up carbon (white portion) of the valve seat with a
If the width is too wide [G], too narrow [H] or uneven [J],
repair the seat (see Valve Seat Repair).
Valve Seating Surface Width
Exhaust 1.2 mm (0.047 in.)
1.2 mm (0.047 in.)
Valve Seat Repair
Repair the valve seat with the valve seat cutters [A].
Special Tools - Valve Seat Cutter Holder Bar [B]: 57001
Valve Seat Cutter Holder, 5 [C]: 57001-1208
[For Exhaust Valve Seat]
Valve Seat Cutter, 45° - 24.5: 57001-1113
Valve Seat Cutter, 32° - 25: 57001-1118
Valve Seat Cutter, 60° - 25: 57001-1328
[For Intake Valve Seat]
Valve Seat Cutter, 45° - 30: 57001-1187
Valve Seat Cutter, 32° - 30: 57001-1120
Valve Seat Cutter, 60° - 30: 57001-1123
If the manufacturer's instructions are not available, use
the following procedure.
ENGINE TOP END 5-23