DETROIT DIESEL
Engine Tune-Up
same positions that they will attain while the engine is
IMPORTANT : The above step should result in
running at full-load.
placing the governor linkage and control tube
assembly in the same position that they will attain
6.
To be sure of the proper rack adjustment, hold
while the engine is running at full load.
the speed control lever in the full-fuel position and press
down on the injector rack with a screw driver or finger tip
7.
To adjust the remaining injector rack control
and note "rotating" movement of the injector control rack
levers, remove the clevis pin from the fuel rod and the
(Fig. 3) when the speed control lever is in the maximum
injector control tube lever, hold the injector control racks
speed position. Hold the speed control lever in the
in the full-fuel position by means of the lever on the end
maximum speed position and, using a screw driver,
of the control tube. Turn down the inner adjusting screw
press downward on the injector control rack. The rack
on the injector rack control lever of the adjacent injector
should tilt downward (Fig. 4) and when the pressure of
until the injector rack has moved into the full-fuel
the screw driver is released, the control rack should
position and the inner adjusting screw is bottomed on
"spring" back upward.
the injector control tube. Turn the outer adjusting screw
down until it bottoms lightly on the injector control tube.
If the rack does not return to its original position, it is too
Then alternately tighten both the inner and outer
loose. To correct this condition, back off the outer
adjusting screws.
adjusting screw slightly and tighten the inner adjusting
screw slightly.
8.
Recheck the rear injector rack to be sure that it
has remained snug on the ball end of the injector rack
The setting is too tight if, when moving the speed control
control lever while adjusting the adjacent injector. If the
lever from the no-speed to the maximum speed
rack of the rear injector has become loose, back off the
position, the injector rack becomes tight before the
inner adjusting screw slightly on the adjacent injector
speed control lever reaches the end of its travel (as
rack control lever. Tighten the outer adjusting screw.
determined by the stop under the governor cover). This
When the settings are correct, the racks of both injectors
will result in a step-up in effort required to move the
must be snug on the ball end of their respective rack
speed control lever to the end of its travel. To correct
control levers.
this condition, back off the inner adjusting screw slightly
and tighten the outer adjusting screw slightly.
NOTE: Overtightening of the injector rack
control
lever
adjusting
screws
during
installation or adjustment can result in damage
to the injector control tube. The recommended
torque of the adjusting screws is 24-36 in-lbs.
Fig 5 - Adjusting Maximum No-Load engine
Fig. 6 - Governor spring Assemblies
Speed (Type A)
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