(3) Check the armature for free rotation. There
(5) Replace the starting motor if it is worn,
must be no catching, binding, or scraping as the
damaged, or inoperative.
armature is rotated.
(4) To check the starting motor solenoid, apply
(1) Position the starting motor (3, fig. 4-26)
24 vdc between the BAT terminal of the solenoid and
with its assembled solenoid switch on the flywheel
the switch (S) terminal. This will advance the starter
housing of the engine; secure with three cap screws (1)
drive to the engaged position. With the drive advanced
and lock washers (2).
and power still applied, check continuity between the
If necessary, refer to figure 1-4 for
BAT and motor (M) terminals Continuity must exist.
Break the circuit to the terminals. The drive must retract
(3) Attempt to start the engine as directed in
fully, and the circuit between the BAT and motor (M)
paragraph 2-3. The starting motor must crank the
terminals must break.
Section XIII. MAINTENANCE OF CONTROLS AND INSTRUMENTS
The engine controls and instruments are
e. The starter disengage relay, mounted on the
mounted on the control panel which is part of the dash
control panel, opens the circuit to the starter solenoid
assembly of the engine. Refer to figure 1-4 for the
switch to deenergize the start circuit immediately when
wiring diagram showing the electrical connections
the engine starts, and prevents the operation of the
between the engine and controls. The function of the
starting motor at any time while the engine is running.
controls and instruments is described in table 2-1.
This protects the starting motor from damage which
b. The engine has three protective devices which
could be caused by accidental operation of the starter
will shut down the engine under certain conditions which
push-button while the engine is running. The operating
could damage the engine. These conditions are high
coil of the relay is connected to alternator output so that
coolant temperature, low oil pressure, and engine
the start circuit is held open whenever there is alternator
overspeed. In each of these emergency conditions, the
engine shutdown is accomplished by grounding the
Control Panel Engine Controls and
primary of the magneto to prevent the engine ignition
system from operating.
c. Two large gages on the engine control panel
a. Removal and Disassembly.
indicate the suction and discharge pressures of their
related systems. They are connected to the pump by
Disconnect the battery cables from the
lines and fittings, and each system incorporates a valve
to disconnect the gage from the system if desired. A
disconnecting any leads to the engine
dampener in the system at each gage prevents
controls and instruments.
momentary pressure surges from damaging the related
prevent shorts which could damage the
alternator, voltage regulator, and other
d. The tachometer-hourmeter mounted on the
control panel is driven by a flexible drive shaft which
(1) Disconnect the electrical leads from the
connects to a drive adapter on the overspeed governor
engine controls and instruments on the control panel.
arm. The drive adapter meshes with a threaded portion
Tag leads to facilitate reassembly.
of the overspeed governor drive shaft, providing the
Remove and disassemble the engine
rotational force necessary to operate the tachometer-
controls and instruments from the control panel as
shown in figure 4-27.