Bench testing
Remove the commutator end cover from the motor and check the
brushes for wear and replace if necessary.
Measuring light running current
Clamp the motor in a vice and, using a 12 volt battery. with a moving
coil ammeter of suitable range, check the light running current and
the armature speed. Always use heavy gauge cabling for this test.
Under light load the motor should run freely with a current of 65
amps at 8000-10,0000 rpm. The test only proves that the motor
functions correctly when not at its normal operating load. If, on
refitting the motor, it again fails to crank the engine an internal
fault is indicated and a replacement motor will need to be fitted.
Starter motor specification
Lock torque 0.97kg/m (7.0 lb/ft) @ 350 amps
Running torque 0.61 kg/m (4.4 lb/ft) @ 260 amps
Light running current 65 amps @ 8-10,000 rpm
Brush spring pressure 800gf (28 ozf)
Charging system
The charging system comprises a battery, alternator and ignition
warning light as shown in Figure 8.
To Next Page
Loading...
