Engine Tune-Up
DETROIT DIESEL
Fig. 7 - Adjusting Buffer Screw
previously performed, to the minimum by backing off
the outer lock nut (Fig. 8) until the end of the booster
spring eye bolt is flush with the end of the nut.
Fig. 8 - Adjusting Booster Spring
3.
Adjust the eye bolt in the slot in the bracket so
that an imaginary line through the booster spring will
Adjust Engine Speed Droop
align with an imaginary center line through the speed
control shaft. Secure the lock nuts on the eye bolt to
The adjustment of the spring tension as outlined under
retain the adjustment.
Adjust Variable Speed Spring Tension will result in
approximately 7% droop from the maximum no-load
4.
Move the speed control lever to the maximum
speed to the full-load speed. This is the optimum droop
speed position and note the force required. To reduce
setting for most applications. However, the droop may
the force, back off the inner lock nut and tighten the
be changed as necessary for a particular engine
outer lock nut to increase the tension on the booster
application.
spring.
1.
Lower the speed droop by increasing the spring
NOTE Before tightening the lock nuts,
tension.
reposition the booster spring as in Step 3.
2.
Raise the speed droop by decreasing the spring
The setting is correct when the speed control lever can
tension.
be moved from the idle speed position to the maximum
speed position with a constant force, while the engine is
NOTE: A change in the variable speed spring
running, and when released it will return to the idle
tension will change the maximum no-load speed
speed position.
and the engine idle speed which must also be
readjusted.
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