DETROIT DIESEL
Engine Tune-Up
required to move the stop lever to the RUN position and a deflection in the fuel rod (fuel rod deflection can be seen at the
bend). If the rack is found to be too tight, back off the inner adjusting screw slightly and tighten the outer adjusting screw.
5. To adjust the remaining injector rack control levers, remove the clevis pin from the fuel rod and the injector control
tube lever, hold the injector control racks in the full-fuel position by means of the lever on the end of the control tube.
Turn down the inner adjusting screw on the injector rack control lever of the adjacent injector until the injector rack has
moved into the full-fuel position and the inner adjusting screw is bottomed on the injector control tube,. Turn the outer
adjusting screw down until it bottoms lightly on the injector control tube. Then alternately tighten both the inner and outer
adjusting screws.
6. Recheck the rear injector rack to be sure that it has remained snug on the ball end of the rack control lever while
adjusting the adjacent injector rack. If the rack of the rear injector has become loose, back off the inner adjusting screw
slightly on the adjacent injector rack control lever and tighten the outer adjusting screw. When the settings are correct,
the racks of both injectors must be snug on the ball end of their respective control levers.
7. Position the remaining injector rack control levers as outlined in Steps 4, 5 and 6.
8. When all of the injector rack control levers are adjusted, recheck their settings. With the control tube lever in the full-
fuel position, check each control rack as in Step 4. All of the control racks must have the same "spring" condition with
the control tube lever in the full-fuel position.
9. Insert the clevis pin in the fuel rod and the injector control tube levers.
Fig. 5 - Locating of Shims and Stops
10. Use a new gasket and replace the valve rocker cover.
Adjust Maximum No-Load Speed
All governors are properly adjusted before leaving the factory. However, if the governor has been reconditioned or
replaced, and to ensure the engine speed will not exceed the recommended no-load speed as given on the option plate,
the maximum no-load speed may be set as follows:
Start the engine and, after it reaches normal operating temperature, determine the maximum no-load speed of the
engine with an accurate tachometer. Then stop the engine and make the following adjustments, if required.
1. Refer to Fig. 8 and disconnect the booster spring and the stop lever retracting spring.
2. Remove the variable speed spring housing and the variable speed spring retainer located inside of the housing.
3. Refer to Table 1 and determine the stops or shims required for the desired full-load speed. Do not use more than
four thick and one thin shim. A split stop can only be used with a solid stop (Fig. 5).
4. Install the variable speed spring retainer and housing and tighten the two bolts.
5. Connect the booster spring and stop lever spring. Start the engine and recheck the maximum no-load speed.
6. required, add shims to obtain the necessary operating speed. For each .001 "in shims added, the operating speed
will increase approximately 2 rpm.
IMPORTANT: If the maximum no-load speed is raised or lowered more than
50 rpm by the
Full Load Speed
STOPS
SHIMS
RPM
Solid Ring
Split Ring
As Required
0
0
2575-2800
As Required
0
1
2101-2575
As Required
1
1
1701-2100
As Required
2
1
1200-1700
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