Engine Tune-Up
2. Move the speed control lever from the idle
speed position to the maximum speed position.
3. Return the speed control lever to the idle
speed position.
NOTE: Movement of the speed control lever is
t o take-up the clearance in the governor
l i n k a g e . The injector rack clevis-to-body
c l e a r a n c e can be increased by turning the
starting aid screw farther in against the gap
adjusting screw, or reduced by backing it out.
IMPORTANT: The starting aid screw will be
ineffective if the speed control lever is advanced
toward wide open throttle during start-up.
2. On early turbocharged engines, adjust the internal
starting aid screw, as follows:
a. With the engine stopped, place the governor stop
Fig. 8 - Adjusting Maximum No-Load Speed
lever in the run position and the speed control
lever in the idle position.
Adjust Maximum No- load Engine Speed
b. Hold the gap adjusting screw, to keep it from
All governors are properly adjusted before leaving the
turning, and adjust the starting aid screw to
factory. However, if the governor has been recondi-
obtain the required setting between the shoulder
tioned or replaced, and to ensure the engine speed will
on the injector rack clevis and the injector body
not exceed the recommended no-load speed as given
(Fig. 7). The setting is measured at the No. 3R
on the option plate, set the maximum no-load speed as
injector rack clevis.
follows:
NOTE: Be sure the buffer screw projects
c. Check the injector rack clevis-to-body clearance
after performing the following:
5/8" from the lock nut to prevent interference
while adjusting the maximum no load speed.
1. Position the stop lever in the run position.
1. Loosen the spring retainer lock nut (Fig. 8) and
back off the high speed spring retainer approximately
2. Move the speed control lever from the idle
five turns.
position to the maximum speed position.
2. With the engine running at operating temperature
3. Return the speed control lever to the idle
and no-load on the engine, place the speed control
position.
lever in the maximum speed position. Turn the high-
speed spring retainer until the engine is operating at
NOTE: Movement of the governor speed control
the recommended no load speed.
lever is to take-up clearances in the governor
linkage. The clevis-to-body clearance can be
3. Hold the high-speed spring retainer and tighten the
increased by backing out the starting aid screw
lock nut.
or reduced by turning it farther into the gap
adjusting screw.
Adjust Idle Speed
d. Start the engine and re-check the running gap
(.0015") and, if necessary, reset it and re-
With the maximum no-load speed properly adjusted,
position the injector racks. Then stop the engine.
adjust the idle speed as follows:
1. With the engine running, at normal operating
e. Use a new gasket and replace the governor cover
temperature and with the buffer screw backed out to
and lever assembly. Tighten the screws.
avoid contact with the differential lever, turn the idle
speed adjusting screw (Fig. 9) until the engine is
3. Use new gaskets and replace the valve rocker covers.
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