Section IV. OPERATION OF EQUIPMENT - TM-5-4320-240-150024

completed, and the starting motor cranks the engine.

safety switch (3, fig. 2-4) indicates the oil pressure of the

The starting motor circuit is broken when the starter

engine lubrication system. The normal oil pressure

button is released.

reading when the engine is running at 2,250 rpm and at

normal operating temperature is between 40 and 50 psi

j. Intake Pressure Gage. The intake pressure gage

(pounds per square inch). The normal oil pressure

(10, fig. 2-4) indicates the pressure or vacuum at the

reading at idle speed (400 to 600 rpm) is over 7 psi.

intake side of the pump. Normal readings are from 30

(2) The engine oil pressure gage includes an

inches of mercury vacuum to 100 psi pressure.

integral oil pressure safety switch which automatically

k. Choke Control. The choke control (8, fig. 2-4) is

shuts off the engine if oil pressure drops below 7 psi. It

mechanically connected to the carburetor choke lever.

includes a reset button at the bottom of the gage. To

The choke is fully closed when the choke control knob is

start the engine after low pressure shutdown, first

pulled out as far as it will go; the choke is open when the

determine and correct the cause of the failure; press the

knob is pushed in as far as it will go. Close the choke to

reset button before starting the engine, following the

facilitate starting a cold engine.

As the engine

normal starting procedures.

temperature rises, operate the choke to the open

e. Throttle Control. The throttle control (9, fig. 2-4)

position until it is fully opened when engine temperature

provides a means of adjusting engine speed. Pulling

rises to normal.

the lever to the fullout position produces full speed

l. Battery Disconnect Switch. The battery disconnect

(2,250 rpm). Pushing the lever to the full-in position

switch (4, fig. 2-4) when opened, breaks the circuit

produces idle speed. f. Fuel Primer Pump Handle. The

between the batteries and the starting motor. The

fuel primer pump handle (1, fig. 2-4) operates the primer

switch must be in the ON position when the pumping

pump used to pump gasoline into the intake manifold for

unit is being started or is operating.

cold weather starting. When ambient temperatures are

m. Safety Bypass Switch. The safety bypass switch

below freezing, pump the handle five or six times before

(14, fig. 2-4) provides a means of overriding the control

starting. Leave the handle in full-in position while the

that automatically shuts down the engine if conditions of

pumping unit is operating.

excessive water temperature or low oil pressure are

g. Discharge Pressure Gage. The discharge pressure

encountered.

gage (13, fig. 2-4) indicates pressures on the discharge

n. Liquid Level Gage. The liquid level gage (13, fig.

side of the pump. Normal gage readings are from 0 to

1-2) is located in the fuel tank (6, fig. 1-2). It indicates

300 psi.

the level of the fuel in the tank.

h. Magneto Switch. The magneto switch (11, fig. 2-4)

o. Liquid Level Control. The liquid level control (17,

when pulled out, closes the magneto circuit. Pull out

fig. 1-2) is located in the fuel tank (18, fig. 1-2). It

before starting the engine. Push to shut off the engine.

controls the level of fuel in the tank when an auxiliary

i. Starter Button. The starter button (12, fig. 2-4)

fuel supply is connected.

when depressed, completes a circuit that actuates the

starting motor. When the starter button is pushed in, a

circuit from the batteries to the starting motor is

Section IV. OPERATION OF EQUIPMENT

pumping unit, basic motions of the pumping unit, and on

2-10. General

coordinating basic motions to perform specific tasks for

a. Instructions in this section are published for

which the equipment is designed. Since nearly every

information and guidance of personnel responsible for

job presents a different problem, the operator may have

operation of the pumping unit.

to vary given procedures to fit the individual job.

b. The operator must know how to perform every

operation of which the pumping unit is capable. This

section gives instructions on starting and stopping the

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