5-24 ENGINE TOP END
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 Seat Repair).
Valve Seating Surface Outside Diameter
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
Inlet, Exhaust 0.5 ∼ 1.0 mm
Valve Seat Repair
Repair the valve seat with the valve seat cutters [A].
Special Tools -
Valve Seat Cutter Holder, 4: 57001-1275 [B]
Valve Seat Cutter Holder Bar: 57001-1128 [C]
[For Inlet Valve Seat]
Valve Seat Cutter, 45° - 24: 57001-1113
Valve Seat Cutter, 32° - 25: 57001-1118
Valve Seat Cutter, 60° - 25: 57001-1328
[For Exhaust Valve Seat]
Valve Seat Cutter, 45° - 27.5: 57001-1114
Valve Seat Cutter, 32° - 28 : 57001-1119
Valve Seat Cutter, 60° - 27: 57001-1409
If the manufacturer's instructions are not available, use
the following procedure.
26.4 ∼ 26.6 mm (1.04 ∼ 1.05 in.)
22.1 ∼ 22.3 mm (0.87 ∼ 0.88 in.)
(0.02 ∼ 0.04 in.)