Engine Tune-Up
DETROIT DIESEL
LIMITING SPEED MECHANICAL GOVERNOR AND INJECTOR RACK CONTROL ADJUSTMENT
6V-53 ENGINE
The limiting speed mechanical governor is mounted at
2.
Back out the buffer screw (Fig. 9) until it
the rear of the engine, between the flywheel housing
extends approximately 5/8" from the lock nut.
and the blower (Fig. 1). The governor is driven by the
right blower rotor drive gear. The left blower rotor drive
CAUTION: Do not back the buffer screw out
gear is driven by a shaft, that passes through the
beyond the limits given, or the control link lever
governor housing, from the engine gear train. There are
may disengage the differential lever.
two types of limiting speed governor assemblies. The
difference in the two governors is in the spring
3.
Start the engine and loosen the idle speed
mechanism (Fig.
7).
One has a long spring
adjusting screw lock nut. Then adjust the idle screw
mechanism, the other has a short spring mechanism.
(Fig. 8) to obtain the desired engine idle speed. Hold
the screw and tighten the lock nut to hold the
After adjusting the exhaust valves and timing the fuel
adjustment.
injectors, adjust the governor and position the injector
rack control, levers.
NOTE: The recommended idle speed for non-
EPA certified engines is 500-600 rpm, but may
NOTE: Before proceeding with the governor
and
vary with special engine applications.
injector rack adjustments, disconnect
any
supplementary governing device.
After
the
4.
Stop the engine, clean and remove the governor
adjustments are completed, re-connect
and
cover and the valve rocker covers. Discard the gaskets.
adjust the supplementary governing device.
5.
Start and run the engine, between 800 and 1000
Adjust Governor Gap
rpm, by manual operation of the differential lever.
With the engine stopped and at operating temperature,
CAUTION: Do not overspeed the engine.
adjust the governor gap as follows:
6.
Check the gap between the low-speed spring
1.
Remove the high-speed spring retainer cover.
cap, and the high-speed spring plunger with a .0015 "
feeler gage. If the gap setting is incorrect, reset the gap
Fig. 1 - Limiting Speed Governor Mounting
Fig. 2 - Adjusting Governor Gap
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