Engine Tune-Up
on the option plate, the maximum no-load speed may
NOTE: Movement of the speed control lever is
be set as follows:
t o take-up the clearance in the governor
l i n k a g e . The injector rack clevis-to-body
clearance can be increased by turning the
ENGINES WITH DUAL-RANGE LIMITING
starting aid screw farther in against the gap
SPEED MECHANICAL GOVERNOR (Fig. 7)
adjusting screw, or reduced by backing it out.
After positioning the injector rack control levers, set
IMPORTANT: The starting aid screw will be
the maximum engine speeds.
ineffective if the speed control lever is advanced
toward wide open throttle during start-up.
IMPORTANT: Be sure the buffer screw projects
5/8" from the lock nut to prevent interference
2. On early turbocharged engines, adjust the internal
while adjusting the maximum no-load speeds.
starting aid screw as follows:
With the spring housing assembly mounted on the
a. With the engine slopped, place the governor stop
governor, the piston and sleeve assembled with four
lever in the run position and the speed control
.100" shims and ten .010" shims and the low
lever in the idle position.
maximum speed screw extending from the spring
housing approximately 1-1/4", proceed as follows:
b. Hold the gap adjusting screw, to keep it from
turning, and adjust the starting aid screw to
obtain the required setting between the shoulder
CAUTION: Do not apply air or oil pressure to
on the injector rack clevis and the injector body
the governor until performing Step 1f.
(Fig. 6). The setting is measured at the No. 3R
injector rack clevis.
1. Set the high maximum no-load speed.
c. Check the injector rack clevis-to-body clearance
a. Start the engine and position the engine speed
after performing the following:
control lever in the maximum speed position.
1. Position the stop lever in the run position.
b. Turn the low maximum speed adjustment screw in
until the high maximum speed desired is
2. Move the speed control lever from the idle
obtained.
position to the maximum speed position.
3. Return the speed control lever to the idle
c. Stop the engine and remove the spring housing
position.
assembly.
NOTE: Movement of the governor speed control
lever is to take-up clearances in the governor
linkage. The clevis-to-body clearance can be
increased by backing out the starting aid screw
or reduced by turning it farther into the gap
adjusting screw.
d. Start the engine and re-check the running gap
(.0015") and, if necessary, reset it and re-
position the injector racks. Then stop the engine.
e. Use a new gasket and replace the governor cover
and lever assembly. Tighten the screws.
f. Use new gaskets and replace the valve rocker
covers.
Adjust Maximum No-load Engine Speed
All governors are properly adjusted before leaving the
factory. However, if the governor has been recondi-
Fig. 7 - Dual-Range Governor (Top View)
tioned or replaced, and to ensure the engine speed will
not exceed the recommended no-load speed as given
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