Motor Problems with Engine

[Anonymous]

I have an engine that I wanted to repaint. I test the engine and it starts to jump back and forth real quick. almost hopping down the track. What is causing this? Is there a short somewhere in the motor? Thanks.

[ben10ben]

It almost sounds to me like you have a dead commutator segment. If this is the case, the motor won't start in certain positions, and, if it does start, will run very jerkily and very hot.

The test for this is to remove the armature and test for continuity between all three segments. If any combination shows any difference in resistance from the other two, this is probably the case.

[1688torpedo]

Hello Brian R & to the forum!   In order to help you more if you can give us more info such as Engine#  (under the cab window) Type of motor(e.g. Can or Pullmor) & age of engine. The problem could be as Ben suggested or it could also be that the Motor needs a good cleaning & some oil & grease also. If it has a Mechanical Reverse unit that too can cause some problems for you. If you happen to have a Scanner handy scan some photo's so we can see what it looks like. Then we'll know how to advise you. My Guess is that both the Reverse Unit & Motor need to be cleaned & possibly a wire or two need to be replaced. Take Care. Hope to hear from you soon.