The most common reason for the motor to periodocly shut off like this is
that it is over heating and the thermol protection system kicks in to
protect the motor.
The most common cause for a motor to over heat; is the belt is simply to
tight. You could have worn pillow bushings, but if they are causing that
much pull on the motor you would hear a god awful noise from them.
To test your belt tension grasp the belt between your thumb and forefinger
and apply light up & down pressure (approximatly 3 lbs). The belt should
only move about 3/4 to 1 inch.
To adjust the belt varies, usually you will find a bolt that holds the
motor mounting bracket. It is usually in a cresent shaped slot. Loosen
this bolt "a little" and move the motor toward the pulley slightly. If
you move it too much, just redo it until you can only move the belt as
above. If the belt is too loose, the worse that can happen is the belt
might slip a little.
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