INSPECTION AND REPAIR OF BASIC ENGINE
6-4
1.4 Inspecting valve face
Apply a thin coat of Shinmyoutan or equivalent lead-free
coloring paste on the valve face, and strike the valve face
against the valve seat using a valve lapper to check for
contact condition. If the contact is not even, or any defects
are found, or if the limit is exceeded, reface or replace the
valve.
Note: (a) Inspect the valve face after the valve guide is
repaired or replaced.
(b) Do not rotate the valve when pressing the valve
face coated with Shinmyoutan or equivalent lead-
free dye against the valve seat.
(c) Always lap the valve and valve seat after the
valve has been refaced or replaced.
Checking valve face
Valve-to-valve seat contact
Valve-to-valve seat contact position
1.5 Refacing valve face
If the valve face is significantly worn out, reface the valve
face using a valve refacer.
Note: (a) Grind the valve face using the valve refacer at the
specified angle.
(b) Secure the valve margin width equal to or greater
than the limit. If the dimensions after refacing
does not meet the specified values, replace the
valve with a new one.
Refacing valve face
Valve lapper
Shinmeitan
Good
Bad
Contact
(must be at face center)
Item Standard Limit
Valve seat
Valve seat angle 44°
–
Valve sinkage
0.4 to 0.6 mm
[0.0158 to 0.0236
in.]
Valve margin
1.0 mm
[0.0394 in.]
0.5 mm
[0.0197
in.]
Valve margin
Valve sinkage
Valve seat
angle
Seat width
Set the valve face
angle at the specified
angle.
Valve refacer
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