DETROIT DIESEL
Engine Tune-Up
torque of the adjusting screws is 24-36 in-Ibs (3-
speed control lever reaches the end of its travel, back
4 Nm).
off the spring retainer a few additional turns.
12. When all of the injector rack control levers are
2. With the engine at operating temperature and no-
adjusted, recheck their settings. With the control tube
load on the engine, place the speed control lever in the
lever in the full-fuel position check each control rack
maximum speed position. Turn the high-speed spring
as in Step 7. All of the control racks must have the
retainer in (Fig. 6) until the engine is operating at the
same "spring" condition with the control tube lever in
recommended no-load speed. Use an accurate hand
the full-fuel position.
tachometer to determine the engine speed. The
maximum no-load speed varies with the full-load
13. Insert the clevis pin in the fuel rod and the injector
operating speed.
control tube levers.
3. Hold the spring retainer and tighten the lock nut.
14. Turn the idle speed adjusting screw in until it
projects 3/16" from the lock nut to permit starting the
engine.
TYPE B GOVERNOR SPRINGS (Fig. 7):
15. Use new gaskets and replace the valve rocker
1. Start the engine and after it reaches normal
covers.
operating temperature, remove the load from the
engine.
Adjust Maximum No-load Engine Speed
2. Place the speed control lever in the maximum speed
position and note the engine speed.
All governors are properly adjusted before leaving the
factory. However, if the governor has been recondi-
tioned or replaced, and to ensure the engine speed will
not exceed the recommended no-load speed as given
on the engine option plate, set the maximum no-load
speed as follows:
TYPE A GOVERNOR SPRINGS (Fig. 7):
I. Loosen the lock nut with a spanner wrench and back
off the high-speed spring retainer several turns. Then
start the engine and increase the speed slowly. If the
speed exceeds the required no-load speed before the
Fig. 6 - Adjusting Maximum No-Load Engine
Fig. 7 - Governor Spring Assemblies
Speed
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