Detroit Diesel — Position Injector Rack Control Levers (Limiting Speed Mechanical Governor 6, 8 and 12V-71)

Adjustments

From a Detroit Diesel service manual — check it applies to your exact model before use.

Procedure

1. Disconnect any linkage attached to the governor speed control lever.
2. Turn idle speed adjusting screw until 1/2 in of threads (12-14 threads) project from lock nut.
3. Back out buffer screw approximately 5/8 in.
4. Remove clevis pin from fuel rod and right cylinder bank injector control tube lever.
5. Loosen all inner and outer injector rack control lever adjusting screws on both cylinder heads.
6. Move speed control lever to maximum speed position; turn No. 1L inner adjusting screw down until slight control lever movement or step-up in effort.
7. Turn outer adjusting screw down until it bottoms lightly on injector control tube; alternately tighten both screws.
8. Press down on injector rack with a screwdriver or finger tip; rack should tilt downward and spring back upward.
9. Adjust No. 1R injector rack as in previous steps.
10. Adjust remaining racks by holding injector control racks in full-fuel position at the control tube lever.
11. Turn idle speed adjusting screw in until it projects 3/16 in from lock nut.
12. Use new gaskets and replace the valve rocker covers.

Source: Detroit Diesel service manual. Steps and values are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.

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