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I think my American flyer 401 has a motor short...

Engine needs a lot of power to run and gets very hot.

I am assuming that the short current is relatively high (put not high enough to trip the circuit breaker), with the current actually going through the motor being low. Once the voltage gets high enough, the current that actually makes it through the motor (and not the short) causes enough motor torque to overcome static friction in the motor. The part thats shorted contributing to the excessive heat.

Am I analyzing this right? If so, should I look to get it re-wound or replaced?

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I just had a problematic engine that ran hot very quickly.  The issue was something that I did not expect and took a while to troubleshoot.

The problem was that the brush plates on the armature were covered in grease/grime that seemed to be burned on.  I used copper cleaner to clean the brush plates, after swapping out the armature and finding that was the problem.  So check the brush plates on the armature and clean them if necessary.

Here is a link to the post I made on the subject, with some photos of the armature brush plates.


Last edited by Nation Wide Lines

also the armature 3 segments can have groves worn into the copper this happens if the brushes wear down to much and either by the brush cocking or the springs contact the commutator ! always change the springs and brushes when repairing the motor and polish commutator with fine polishing cloth or very fine emery paper/ copper should look like a mirror after being polished !

actually also the field winding or armature winding cook be cooked from overheating look at the actual winding for dark color the winding should be bright color not dark!


Last edited by Alan Mancus

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