Install the high-speed spring cover and tighten the two bolts.
Adjust Buffer Screw
With the idle speed properly set, adjust the buffer
screw as follows:
1.
With the engine running at normal operating temperature, turn the buffer screw in (Fig. 8) so it contacts the
differential lever as lightly as possible and still eliminates engine roll.
NOTE: Do not increase the engine idle speed more than 15 rpm with the buffer screw.
2.
Recheck the maximum no-load speed. If it has increased more than 25 rpm, back off the buffer screw until the
increase is less than 25 rpm.
3.
Hold the buffer screw and tighten the lock nut.
Fig. 7 Adjusting Buffer Screw
Page 83
DETROIT DIESEL
Engine Tune Up
