Starter Switch

TM 5-4320-273-14

the engine to operate at the governed speed.

pressure must be 4 to 5 pounds per square inch. When

the oil is cold, pressure will be higher.

c. Starter Switch. The starter switch (5) when

pressed permits current to flow from the battery to

k. Low Oil Pressure Safety Switch. The low oil

the starting motor to crank the engine for starting.

pressure safety switch plunger (7) stops the engine by

closing the ground circuit to the magneto when the

d. Ignition Switch. The ignition switch (6) controls

lubricating oil pressure falls below 1 pound per

the ignition circuit. When in the ON position, it per-

mits a high-tension current to be transmitted from

square inch. It must be manually set each time the

engine is started.

the magneto to the spark plugs. When in the OFF

1. Fuel Hand Primer Lever. The fuel hand primer

position, it shorts out the magneto coil and stops the

lever (1, fig. 2-2) is operated in a back-and-forth

engine.

motion to pump fuel to prime the fuel lines at initial

e. Ammeter. The ammeter (3) indicates if the bat-

starting or after the engine has been idle for an ex-

tery is being charged or discharged while the engine

tended period of time.

is in operation. The ammeter should show a high

charge rate to restore battery energy immediately af-

ter starting and then taper off to zero with continued

operation.

f. T a c h o m e t e r - H o u r m e t e r . The tachometer-

hourmeter (8) registers the rpm of the engine and

maintains a running total of the engine operating

hours and tenths of hours.

g. Engine Vacuum Gage. The engine vacuum gage

(10) is a measure of the engine horsepower output.

The horsepower required to drive the pump varies

with the weight of the liquid being pumped and the

capacity or rate of pumping. For example, jet fuel

having a specific gravity of 0.8 requires only eight-

tenths as much horsepower at a given flow rate as

does water having a specific gravity of LO. The

vacuum reading on the engine vacuum gage is in-

dicative of the horsepower being generated - the

higher the vacuum, the less the horsepower.

h. Pump Suction Gage. The pump suction gage (11)

indcates either a vacuum or pressure at the pump

inlet, depending on pump application.

i. Pump Discharge Pressure Cage. The pump

1. Hand primer lever

pressure gage (9) indicates discharge pressure at the

2. Fuel pump

pump outlet.

2-2. Fuel hand

Figure

primer lever.

j. Oil Pressure Cage. The oil pressure gage (4) in-

dicates the oil pressure within the lubricating

The fuel gage (6, fig. 2-3) indicates

m. Fuel Cage.

system. At normal operating temperature, the oil

the level of fuel in the fuel tank.

2-2