Service manual
ENGINE
ADJUSTMENTS
VALVE
CLEARANCE
ADJUSTMENT
1.
Warm the engine to normal operating temperature.
2. Pull off the
air breather pipe from the rocker cover, and
take off the rocker cover bolts and the rocker cover to
expose the rocker shaft and valve assembly.
3.
Remove the glow plugs from each of the cylinders to
enable the engine to be easily rotated
by
hand to position
each cylinder for valve adjustment.
Valves are adjusted with the piston in the cylinder being
adjusted at
TDC
(top dead clearance)
of
its compression
stroke.
NOTE:
Retorque the cylinder head bolts before adjusting the
engine
s valves.
4. Loosen the head bolts in the reverse order
of
tightening.
CYLINDER
HEAD
BOLT
PATTERN
19
15
16
17
13
• 5
4'
12
FRONT'
5.
Tighten the head bolts in the order shown.
Cylinder
Head
Bolt
Tightening Torque
71 B 11.8 - 12.5
m-kg
(85 - 89 ft-lb)
71 C
11.0
-11.7
m-kg
(80 - 85 ft-lb)
6. Set the piston
of
No. 1 cylinder
to
TDC (compression)
and check the valve clearance at each position indicated.
Adjust,
if
the clearance is incorrect.
Intake
- No. 1 and
No.2
cylinders
Exhaust -
No.1
and
No.3
cylinders
,VALVE
ADJUSTMENT
SEQUENCE
WHEN
NO
4
CYLINDER
IS
AT
TOP
DEAD
CENTER
4 4 3 2
4
EXH~IJST
I 12
EX~AUST
4
INTAKE
3
INTAKE
2
INTAKE
1
INTAKE
3
EX~AUST
11
EXH~USTI
3 2 1 1
.
WHEN
NO
1
CYLINDER
IS
AT
TOP
DEAD
CENTER
.
7. Tum the crankshaft once, setting the piston
of
No.4
cylinder at TDC (compression) and adjust to the
following values:
Intake -
No.3
and
No.4
cylinders
Exhaust -
No.2
and
No.4
cylinders
8. Adjust each valve's clearance by inserting a
0.012 in
(0.03 mm) feeler gauge between the rocker arm and the
valve stem. Make sure to adjust all valves when the
engine is cold.
9. Install the cylinder head cover.
,
Head
Cover
Bolt
Torq~e
..
.
VALVE
CLEARANCE
.71
Bn1
C 0.3 - 0.45
m-kg
(2
- 3 ft-lb)
ENGINE
COMPRESSION
Check the compression pressure.
To
do this warm the engine,
remove all fuel injectors, or glow plugs, disconnect the fuel
shut-off solenoid wire, and install a compression adapter in
the injector hole or glow plug hole, Connect a compression
tester on the adapter and crank the engine with the starter
motor until the pressure reaches a maximum value. Repeat
this process for each cylinder. Look for cylinders with dra-
matically (at least
20%)
lower compression than the average
of
the others. Compression pressure should not differ by
more than 42.7 psi
(3.0 kg/cm2) at 200
rpm.
Compression
Pressure
Standard
71Bn1C
30.0
kglcm
2
(4271b/in2)
at
200 rpm
Compression
Pressure
Limit
71
Bn1C
27.0
kg/cm2 (3841hlinl)
at
200 rpm
MEASURING
COMPRESSION
Engines & Generators
35