EM-24
ENGINE MECHANICAL —
Cylinder Head
(b)
Check the valve seating position.
Apply a thin coat of prussian blue (or white lead) to
the valve face. Install the valve. While applying light
pressure to the valve, rotate the valve against the
seat.
(c)
Check the valve face and seat for the following:
• If blue appears 360° around the face, the valve is
concentric. If not, replace the valve.
• If blue appears 360° around the valve seat, the
guide and seat are concentric. If not, resurface the
seat.
• Check that the seat contact is on the middle of the
valve face with the following width:
Intake
1.1 — 1.7 mm (0.043 — 0.067 in.)
Exhaust 1.4 — 2.0 mm (0.055 — 0.079 in.)
If not, correct the valve seat as follows:
(1)
(Intake)
If the seating is too high on the valve face, use
25° (IN) and 45° cutters to correct the seat.
(2)
If the seating is too low on the valve face, use
70° (IN) or 65° (EX) and 45° cutters to correct
the seat.
(d)
Hand-lap the valve and valve seat with an abrasive
compound.
(e)
After hand-lapping, clean the valve and valve seat.