Free Speed Inspection

Fig. 12 Motor Free Speed Inspection.:

This test is performed during bench testing. With the circuit connected, use a tachometer to measure armature revolutions per minute. Failure of the motor to perform to specifications may be due to light or dry bearings, or high resistance connections. Starter motors do not require lubrication except during overhaul. At this time a couple drops of light oil may be applied to bearings.