TM 5-4220-211-12&P
FUEL SYSTEM/GOVERNOR
A-9.
SPEED ADJUSTMENT.
a. Maximum governor speed is set at the factory and normally requires no adjustment. Figure A-70 shows a
typical governor with low, midrange and full load springs. Refer to the service parts book for alternative springs and other
governor parts when special governor characteristics are required.
b.
If new components are fitted, the governor speed should be set on a test bench so that engine rpm may be
observed.
CAUTION
Careless adjustment or spring selection may cause the engine to
race, resulting serious engine damage.
c. Engine speed adjustment is possible in a range of about 100 rpm by altering the tension of the governor
springs through a few turns of the cross slotted nuts. Tighten them to increase engine speed; loosen to reduce speed.
d. For larger variations in engine speed, change the governor springs. To change them with disassembling the
engine, remove the oval cover located behind the throttle lever. NOTE: On Models 15A430 and 18A430, the injection
pump must e removed before the governor springs can be adjusted. The springs may be adjusted or removed through the
injection pump opening.
Figure A-69. Engine Speed Governing System
A-26
