15 - Engine
75 - Starter Motor
00 - General
15 - 101
9813/5200-2
15 - 101
00 - General
Introduction
..................................................
15-101
Health and Safety
........................................
15-102
Component Identification
.............................
15-103
Check (Condition)
........................................
15-104
Remove and Install
.....................................
15-106
Introduction
The electric starter motor is either a permanent-
magnet or a series-parallel wound direct current
electric motor with a starter solenoid mounted on to
it. When the current from the battery is applied to the
solenoid, through the key-operated ignition switch,
the solenoid engages a lever that pushes out the
drive pinion on the starter driveshaft and meshes the
pinion with the starter ring gear on the flywheel of the
engine.
The solenoid also closes high current contacts for the
starter motor, which begins to turn. Once the engine
starts, the key-operated ignition switch is opened,
a spring in the solenoid assembly pulls the pinion
gear away from the ring gear, and the starter motor
stops. The starter motor pinion is clutched to the drive
shaft through an overrunning clutch which permits
the pinion to transmit drive in only one direction. Drive
is then transmitted through the pinion to the flywheel
ring gear, but if the pinion remains engaged (as for
example because the operator fails to release the
key as soon as the engine starts, or if there is a short
and the solenoid remains engaged), the pinion will
spin independently of the drive shaft, this prevents
the engine driving the starter.
The starter motor is only designed for intermittent
use, the electrical components are designed only to
operate for a time period of 20 s before overheating.
