Engine Tune-Up
lever until the injector rack has moved into the full-
Adjust Starting Aid Screw
fuel position. Turn the outer adjusting screw down
until it bottoms lightly on the injector control tube.
The starting aid screw (Fig. 7) is threaded into the
Then alternately tighten both the inner and outer
governor housing of current engines and into the
adjusting screws.
governor gap adjusting screw of early engines. This
screw is adjusted to position the injector racks at less
than full fuel when the governor speed control lever is
NOTE: Overtightening of the injector rack
in the idle position. The reduced fuel makes starting
control lever adjusting screws during installa-
easier and reduces the amount of smoke on start-up.
tion or adjustment can result in damage to the
injector control tube. The recommended torque
IMPORTANT: The effectiveness of the starting
of the adjusting screws is 24-36 in-lb(3-4 Nm).
aid screw will be eliminated if the speed control
lever is advanced to wide open throttle during
12. Recheck the No. 4R injector rack to be sure it has
starting.
remained snug on the ball end of the injector rack
control lever. If the rack of the No. 4R injector has
After the normal governor running gap of .0015" has
become loose, back off the inner adjusting screw
been set and the injector racks positioned. adjust the
slightly on the No. 3R injector rack control lever and
starting aid screw.
tighten the outer adjusting screw. When the settings
are correct, both injector racks must respond in the
1 . On current turbocharged engines. adjust the
same manner on the ball ends of the control levers
external starting aid screw as follows:
when the injector control tube lever is held in the full-
fuel position.
a. With the engine stopped, place the governor stop
lever in the run position and the speed control
13. Position the remaining injector rack control levers
lever in the idle speed position.
o n the right front cylinder bank as outlined in
Steps 11 and 12.
b. Adjust the starting a i d screw to obtain the
required setting between the shoulder on the
14. Adjust the remaining injector rack control levers
injector rack clevis and the injector body (Fig. 7).
on the right rear. left front and left rear cylinder
Select the proper gage and measure the setting at
banks in the same manner as outlined in Steps 11, 12
any convenient cylinder. When the starting aid
and 13.
screw is properly adjusted. the gage should have a
small clearance of 1/64" (.397 mm) in the space
15. Install the four fuel rod to control tube lever clevis
along the injector rack shaft between the rack
pins and check the adjustment of the injector rack
clevis and the injector body,
control levers.
c. After completing the adjustment, hold the starting
16. Turn the idle speed adjusting screw in until it
aid screw and tighten the lock nut.
projects 3/16" from the lock nut, to permit starting
the engine.
d. Check the injector rack clevis-to-body clearance
after performing the following.
17. Use new gaskets and replace the valve rocker
covers
1. Position the stop lever in the run position.
Fig. 7 - Starting Aid Screw Adjustment
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