Engine Tune-Up
the push rod to obtain a smooth "pull" on the feeler
Exhaust Valve Clearonce Adjustment (Cold
gage.
Engine)
6. Remove the feeler gage. Hold the push rod with a
All of the exhaust valves may be adjusted. in firing
5/16" wrench and tighten the lock nut with a
order sequence. during one full revolution of the
1 / 2 " wrench
crankshaft. Refer to the General Specifications at the
front of the manual for the engine firing order.
7. Recheck the clearance. At this time, if the
adjustment is correct. the .015" feeler gage will pass
1. Place the governor stop lever in the no fuel
freely between the valve bridge and the rocker arm
position.
pallet, but the .017" feeler gage will not pass through.
2. Clean the loose dirt from the valve rocker covers
8. Check and adjust the remaining valves in the same
and remove the covres Then cover any drain cavities
manner as outlined above.
in the cylinder head to prevent foreign material from
entering.
Exhaust Valve Clearance Adjustment (Hot
NOTE: On certain 12V turbocharged engines, it
Engine)
is necessary to remove the air inlet housing to
remove the rocker covers.
Maintaining normal engine operating temperature is
particularly important when making the final valve
3. Rotate the crankshaft, with the starring motor or
clearance adjustment. If the engine is allowed to cool
engine barring tool J 22582, until the injector follower
off before setting any of the valves, the clearance when
is flully depresed on the cylinder to be adjusted.
running at full load may become insufficient.
CAUTION: If a wrench is used on the crankshaft
1. With the engine at normal operating temperature
or camshaft bolt at the front of the engine. do
(160-185F or 71-85C), recheck the exhaust valve
not turn the engine in a left hand direction of
clearance with feeler gage J 9708. At this time, if the
rotation as the bolt will be loosened.
valve clearance is corrret, the .013" feeler gage will
pass freely between the valve bridge and the rocker
4. Loosen the exhaust valve rocker arm push rod lock
arm pallet, but the .015" gage will not pass through.
nut.
Readjust the push rod. if necessary.
2. After the exhaust valve clearance has been adjusted,
5. Place a .017" feeler gage. J 9708, between the valve
check the fuel injector timing.
bridge and the valve rocker arm pallet (Fig. 3). Adjust
TIMING FUEL INJECTOR
2. Rotate the crankshaft, by using the starting motor
To time an injector properly, the injector follower
or engine barring tool J 22582, until the exhaust
must be adjusted to a definite height in relation to the
valves are fully depressed on the particular cylinder to
injector body.
be timed.
All of the injectors can be timed, in firing order
CAUTION: If a wrench is used on the crankshaft
sequence, during one full revolution of the crankshaft.
bolt or camshaft nut at the front of the engine,
Refer to the General Specifications at the front of the
do not turn the engine in a left- hand direction
manual for the engine firing order.
or the bolt or nut will be loosened.
Use the proper timing gage as indicated in Table 1.
3. Place the small end of the injector timing gage in
the hole provided in the top of the injector body, with
the flat of the gage toward the injector follower
Time Fuel Injector
(Fig. 4).
After the exhaust valve clearance has been adjusted,
4. Loosen the exhaust valve rocker arm push rod lock
time the fuel injectors as follows:
nut.
5. Turn the push rod and adjust the injector rocker
1. Place the speed control lever in the idle speed
arm until the extended part of the gage will just pass
position. If a stop lever is provided, secure it in the no
over the top of the injector follower.
fuel position.
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