Engine Tune-Up
NOTE: When checking this distance, the piston
should be held tight against the adjustment
screw of the cover that is held in position, with
its gasket, against t h e e n d o f t h e s p r i n g
housing.
e. Remove the quantity of shims, from the shims
within the piston, equal to the distance noted in
Step d.
f. Start the engine and position the engine speed
control lever in the maximum speed position and
apply air pressure to the governor and note the
engine speed.
g. Remove the air pressure from the governor and
stop the engine, then install or remove shims as
required to obtain the correct high maximum no-
load speed. Removing shims will decrease the
engine speed and adding shims will increase the
engine speed.
Fig. 8 - Adjusting Maximum No-Load Speed
NOTE: Each .010" shim removed or added will
decrease or increase the engine speed approxi-
CAUTION: Do not permit the seal ring on the
mately 10 rpm.
piston to slide past the air inlet port, since the
seal ring will be damaged.
2. Set the low maximum no load engine speed.
d. Note the distance ("X" distance, Fig. 7) the piston
is from the bottom of the spring housing when it
a. Adjust the low maximum speed adjusting screw,
is against the low maximum speed screw, then
with the engine speed control lever held in the
remove the sleeve from the piston
maximum speed position, until the desired low
maximum speed is obtained. Turn the screw in to
increase or out to decrease the engine speed.
b. Recheck the engine speed and readjust if
necessary.
3. Check both the high maximum and low maximum
engine speeds. Make any adjustment that is necessary
as outlined in Steps 1 and 2.
ENGINES WITH STANDARD LIMITING SPEED
MECHANICAL GOVERNOR (Fig. 8)
After positioning the injector rack control levers, set
the maximum no-load engine speed as follows:
NOTE: Be sure the buffer screw projects 5/8"
from the lock nut to prevent interference while
adjusting the maximum no-load speed.
1. Loosen the spring retainer lock nut (Fig. 8) and
back off the high-speed spring retainer approximately
five turns.
Fig. 9 - Adjusting Engine Idle Speed
2. With the engine running at operating temperature
and no-load on the engine, place the speed control
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