Service manual
ENGINE
INSPECTION
VALVE
SPRING
1.
Free Length Check. Measure
the
free
length of
the
valve spring
and
if
free
length is less than
the
limit,
replace
it.
Valve
Spring
Limit
71 B
Inner
spring
42
mm
(1.654 in)
43.6
mm
(2.083 in)
43.6
mm
(1.
717
in)
52.9
mm
(1.717 in)
71C
Outer spring
Inner
spring
Outer spring
2.
Squareness Check. Check the
squareness
of
the
valve
spring
and,
if
it
is
more than the limit, replace
the
spring.
Squareness
Limit
71
Bn1
C
1.25
mm
(0.049 in)
1.37
mm
(0.054 in)
3.
Fitting Pressure Check. Check
the
valve
spring
fitting
pressure
with
a valve spring tester
and,
if
the
pressure
is
less
than
the
limit, replace the spring.
NOTE:
Measure the fitting pressure after compressing the
spring several times.
71
Bn1
C
Spring
Fitting Pressure
Inner
Spring
Outer
Spring
Fitting
Length
37.8
mm (1.49 in)
40.3
nun
(1.59 in)
Fitting
Pressure
Limit
1013
kg
(22.7Ib)
14.5
kg
(32.0
lb)
VALVE
SPRING
TESTER
~SJ
TESTING
THE
SPRING
FIniNG
PRESSURE
,>",
SPECIMEN
VALVE
SPRING
VALVE
GUIDE
1. Inspecting
clearance
between valve and guide.
Set a dial gauge with a magnet and check
the
clearance
between
the
valve stem and the valve
guide.
If
the
clearance
is
more than the limit, replace the valve or
valve
guide.
Clearance
Limit
0.127
mm
(0.005 in)
2.
Valve guide replacement.
To
remove
the
valve
guide,
press out
the
valve guide towards the combustion
chamber
side, using
the
valve guide installer (49 0636
165A).
Again
using
the
valve guide installer, press in
the
valve
guide
into
the
cylinder head until the valve guide height reaches
the
indicated scale on the valve guide installer.
NOTE:
Be sure to press in the
valve
guide so that the inside
chamber on the valve
guide
end
faces
to the combustion
chamber side.
After
the
pressure
fit, check the length
of
the
protruding portion
of
the
valve
guide.
Protrusion
Standard
71
Bn1C
16.5mm(0.650in)
HEIGHT
ABOVE
THE
SPRING
SEAT
16.5
mm
(0.65 in)
VALVE
GUIDE
INSTALLER
Engines & Generators
15