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