DETROIT DIESEL
Engine Tune-Up
V AR IAB L E S P E E D ME C HANIC AL G O V E R NO R ( E NC L O S E D L INK AG E ) AND
INJ E C T O R R AC K C O NT R O L AD J US T ME NT
IN-LINE ENGINES
The single-weight variable speed governor is mounted on the rear end plate of the engine aid is driven by a gear that
extends through the end plate and meshes with either the camshaft gear or the balance shaft gear, depending upon the
engine model.
After adjusting the exhaust valves and timing the fuel injectors, adjust the governor and position the injector rack control
NOTE: Before proceeding with the governor and
injector
rack
adjustments,
disconnect
any
supplementary governing device.
After the
adjustments are completed, reconnect and adjust
the supplementary governing device.
Adjust Governor Gap
With the engine stopped and at operating temperature, adjust the governor gap as follows:
1. Disconnect any linkage attached to the governor levers.
2. Back out the buffer screw until it extends approximately 5/8" from the lock nut.
3. Clean and remove the governor cover and valve rocker cover. Discard the gaskets.
4. Place the spee control lever (Fig. 1) in the maximum speed position.
5. Insert a .006 " feeler gage between the spring plunger and the plunger guide as shown in Fig. 1. If required, loosen
the lock nut and turn the gap adjusting screw in or out until a slight drag is noted on the feeler gage.
6. Hold the adjusting screw and tighten the lock nut. Check the gap and readjust if necessary.
7. Use a new gasket and install the governor cover as follows:
a. Place the cover on the governor housing, with the
Fig. 2 -Positioning the Rear Injector Rack
Control Lever
Fig. 1 - Checking Governor Gap
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