TM 5-3895-359-14&P
MECHANICAL GOVERNOR
With the fuel rod connected to the injector control tube
Horsepower requirements on an engine may vary due to
lever, the mechanism should be free from bind
fluctuating loads; therefore, some method must be
throughout the entire travel of the injector racks. If
provided to control the amount of fuel required to hold
friction exists in the mechanism, it may be located and
the engine speed reasonably constant during load
corrected as follows:
fluctuations. To accomplish this control, a governor is
introduced in the linkage between the throttle control
1. If an injector rack sticks or moves too hard, it may be
and the fuel injectors. The governor is mounted on the
due to the injector hold-down clamp being too tight or
front end of the blower and is driven by the upper blower
improperly positioned. To correct this condition, loosen
rotor. A variable speed governor is used since the
the injector clamp, reposition it and tighten the clamp
engine is subjected to varying load conditions that
bolt to 20-25 Ib-ft (27-34 Nm) torque.
requires automatic fuel compensation to maintain a near
constant speed which may be changed manually by the
2. An injector which is not functioning properly may
operator.
have a defective plunger and bushing or a bent injector
rack. Recondition a faulty injector as outlined on Page
The governor has an identification plate located on the
3-16.
control housing, containing the governor assembly
number, type, idle speed range and drive ratio. The
3. An injector rack may bind as the result of an
maximum engine speed not shown on the identification
improperly positioned rack control lever. Loosen the
plate, is stamped on the option plate attached to the
rack control lever adjusting screws. If this relieves the
valve rocker cover.
bind, relocate the lever on the control tube and position
the rack as outlined in Chapter 10.
Check Governor Operation
4. The injector control tube may bind in its support
Governor difficulties are usually indicated by speed
brackets, thus preventing free movement of the injector
variations of the engine; however, it does not
racks to their no-fuel position due to tension of the return
necessarily mean that all such speed fluctuations are
spring. This condition may be corrected by loosening
caused by the governor. Therefore, when improper
and realigning the control tube supporting brackets. If
speed variations are present, check the engine as
the control tube support brackets were loosened,
follows: 1. Make sure the speed changes are not the
realigned and tightened, the injector racks must be
result of excessive load fluctuations.
repositioned as outlined in Chapter 10.
2. Check the engine to be sure that all of the cylinders
5. A bent injector control tube return spring may cause
are firing properly (refer to Page 10-9-11). If any
friction in the operation of the injector control tube. If
cylinder is not firing properly, remove the injector, test it
the spring has been bent or otherwise distorted, install a
and, if necessary, recondition it as outlined on Page 10-
new spring.
3-16.
6. Check for bind at the pin which connects the fuel rod
3. Check for bind that may exist in the governor
to the injector control tube lever; replace the pin, if
operating mechanism or in the linkage between the
necessary.
governor and the injector control tube.
If, after making these checks, the governor fails to
control the engine properly, remove and recondition the
governor.
10-3-38
