Service manual

ENGINE INSPECTION
CYLINDER HEAD
1. Visual Inspection. Check the cylinder head for cracks
or any other damage and,
if necessary, repair or replace it.
2. Distortion Inspection. Measure the cylinder head
surface distortion
with a straight edge and the thickness
gauge. Take 6 measuring positions as shown in the diagram.
IT the distortion exceeds permissible limit, replace the
cylinder head. (The
head has no allowance for planing and
must
be replaced, not renewed.)
Cylinder
Head Distortion Limit
71 ani C Positions: 1, 2 0.10 mm (0.004 in)
3,4,5, 6 0.25 mm (0.010 in)
FEELER GAUGE ~
2·
!-~~~-&::"""~-e~~~~~~~~5
6
1.
3. Insert Inspection. Check for cracks or damage on the
insert and,
if detected, replace it.
4. Insert Replacement. To remove the insert, place a
suitable
drift into the injection nozzle hole, then tap the drift
with a hammer. To install, set the insert in position and insert
the welch washer into the insert guide hole. Secure the welch
washer by tapping the raised center of the welch washer.
REMOVING THE.
I INSERT
a Use a new welch washer.
h. Insert the welch
washer so that its convex surface
is toward the
cylinder head gasket.
c. After installation, check to see if the insert is
completely fixed
in place.
i WELCH WASHER"'-..
VALVE SEAT
NOTE: Valve seat inserts cannot be fitted to this engine.
1. Valve Seat Angle. Valve seat angle is 45° and 30°
respectively for intake and exhaust sides. The standard
contact width of the valve seat is 2.0 mm (0.08 in) for both
intake and exhaust sides.
If the valve margin is less than the
pennissible
limit, replace the valve.
Mllve margin limit
71 ani C 1.35 mm (0.053 in)
12mm(.08 in)
Engines & Generators
13
"I 3{7 mm (1.25 in)
EXHAUST