Quote:
Catskynr,
I'm interested to hear you say that. I remember asking about what causes the screech some time ago but nobody had a good answer. When I removed mine and bench tested it, it would not make the noise, but it always would when installed in the car, which made it quite difficult to troubleshoot. Can you explain the mechanics of why the armature touching the magnets would cause the squealing noise?
ianc
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With the motor outboard, the weight on the shaft is no longer there, especially if the squirrel cage is removed; no centripetal force or rotational mass. With the unit outboard, you also have much less resistance in airflow on the squirrel cage, which is also centripetal force.
From worst to best - With the coil coming in contact with the collar, you now have a squealing metal tire as the coil should float, not contact; the function of the shaft and bushings. You get a distinct gring with this also. Eventually your magneto is burned out (dead short and destroyed windings) and no more motor. If the bushing allows the shaft to contact the case, you have the squeal; the shaft should ride in the bushing. If the bushing is binding the shaft from turning, same effect, but you’re on your way to destroying the bushing. This is why you want to clean and check the tolerance of the shaft. If the shaft is loose, fix it before disaster strikes and destroys your windings (coil).