l Check end face of each valve stem for wear.
This face meets rocker arm intermittently
‘in operation, and might become concaved or
otherwise irregular. As necessary, smoothen
the end face with an oil stone and, if this
grinding removes the end stock by as much as
0.5 mm (0.0196 in.) (as measured from the
original face), replace the valve.
Limit on stock allowance
0.5
mm
of valve stem end face
(0.0196 in.)
l Check each valve for radial runout with a
dial gauge and
“V”
block. To check runout,
rotate valve slowly. If runout exceeds limit,
replace valve.
I
Limit on valve head
radial runout
0.08
mm (0.003 in.)
I
Fig.
3-612
Valve Seats
CAUTION :
Valves to be checked and serviced for seat-
ing width and contact pattern must be those
found satisfactory in regard to stem clearan-
ce in the guide and also requirements stated
on preceding page under valves.
l
Seating contact width:
Produce contact pattern on each valve in the
usual manner, namely, by giving uniform coat
of marking compound to valve seat and by
rotatingly tapping seat with valve head.
Valve lapper (tool used in valve lapping)
must be used.
The pattern produced on seating face of valve
must be a continuous ring without any break,
and width
6@
of pattern must be within
stated range as follows.
width revealed
1.3-
1.5 mm
(0.0512
-
0.0590 in.)
Fig.
3-5-13
Fig. 3-5-14
@
Valve seat contact width
3-21
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