SECTION III
TM 5-3820-245-14&P
STARTING SYSTEMS
ELECTRICAL STARTING SYSTEMS
The electrical system on the engine generally consists of a battery-charging alternator, a starting motor, voltage regulator,
storage battery, starter switch and the necessary wiring. Additional electrical equipment may be installed on the engine
unit at the option of the owner.
Starting Motor
The starting motor has a Sprag overrunning clutch. Pressing the starting switch engages the starting motor pinion with the
teeth of the flywheel ring gear and energizes the starting motor. The starting motor drives the pinion and rotates the
crankshaft. When the engine begins to operate, the Sprag clutch permits the pinion to overrun on its shaft, until the
starting switch is released, and prevents over-speeding the starting motor.
Starter Switch
To start the engine, a switch is used to energize the starting motor. Release the switch immediately after the engine
starts.
The battery-charging alternator provides the electrical current required to maintain the storage battery in a charged
condition and to supply sufficient current to carry any other electrical load requirements up to the rated capacity of the
alternator.
Regulator
A voltage regulator is introduced into the electrical system to regulate the voltage and current output of the battery-
charging alternator and to maintain a fully charged storage battery.
Storage Battery
The lead-acid storage battery is an electrochemical device for converting chemical energy into electrical energy.
The battery has three major functions:
1. It provides a source of electrical power for starting the engine.
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