DETROIT DIESEL
Engine Tune-Up
11.
Position the remaining injector rack control
is 500 rpm. However, the idle speed may vary with
levers as outlined in Steps 9 and 10.
special engine applications.
3.
Hold the idle speed adjusting screw and tighten
Adjust Maximum No-Load Speed
the lock nut.
1.
With the engine running, move the speed
Adjust Buffer Screw
control lever to the maximum speed position. Use an
accurate tachometer to determine the no-load speed of
the engine.
1.
With the engine running at idle speed, turn the
buffer screw in (Fig. 7) so that it contacts the stop lever
NOTE: Do not overspeed the engine.
as lightly as possible and still eliminates engine roll.
2.
Loosen the lock nut and adjust the maximum
NOTE: Do not raise the engine idle speed more
speed adjusting screw (Fig. 5) until the required no-load
than 20 rpm with the buffer screw. Check the
speed is obtained.
maximum no-load speed to make sure it has not
increased over 25 rpm by the buffer screw
3.
Hold the adjusting screw and tighten the lock
setting.
nut.
Adjust Governor Booster Spring
Adjust Engine Idle Speed
The governor booster spring is used on some engines to
1.
Make sure the stop lever is in the run position
reduce the force necessary to move the speed control
and place the speed control lever in the idle position.
lever from the idle speed position to the maximum
speed position. Adjust the booster spring as follows:
2.
With the engine running at normal operating
temperature, loosen the lock nut and turn the idle speed
1.
Move the speed control lever to the idle speed
adjusting screw (Fig. 6) until the engine idles at the
position.
recommended speed. The recommended idle speed
2.
Reduce the tension on the booster spring, if not
Fig. 6 Adjusting Idle Speed
Fig. 5 - Adjusting Maximum No-Load Engine
Speed
Page 89
