REPAIR OF ENGINE COMPONENTS
Section I. GENERAL
Only those components which are solely within the
This chapter provides you with repair and overhaul
scope of direct and general support maintenance are
instructions for various engine components. It includes
covered. For repair of components which are within the
information regarding disassembly, inspection of parts,
scope of operator/crew and organizational maintenance,
repair, and overhaul.
refer to TM 5-4320-234-12.
Section II. REPAIR OF GOVERNOR
carburetor and as the engine speed tends to increase,
the throttle is closed slightly, decreasing the engine
speed. The decrease in engine speed decreases the
Engine speed is controlled by the inter-operation
centrifugal force of the balls, and the dished race moves
of the governor and the carburetor. The governor is a
axially toward the balls. This movement is sensed by
variable-speed type and is driven by the timing gear on
the fork which, in turn, transfers the movement to the
the end of the camshaft. The driver on the drive shaft
external governing lever. The governing lever opens
of the centrifugal flyball governor engages four
the carburetor throttle, increasing the engine speed. In
hardened steel balls. As the engine runs, centrifugal
this manner, a balanced condition is reached, and the
force throws the balls outward. As the engine speed
engine speed remains constant at the level determined
increases, the centrifugal force increases. This causes
by the throttle control setting.
Adjustment of the
the balls to exert pressure against a dished race, forcing
governor is made by changing the tension of the spring
the race to move axially away from the rotating balls.
which applies tens ion to the external governing lever
The movement of the dished race is transferred to a
and tends to keep the dished race against the flyballs.
drive fork through a thrust bearing. The fork is pinned to
Tightening the spring raises engine speed at any
the governing shaft which pivots as the drive fork
particular throttle control setting. Decreasing spring
moves. An external governing lever on the end of the
tension lowers the speed.
control shaft is connected to the throttle control on the