The low-effort fix for a Marx motor

Last Updated on April 23, 2017 by Dave Farquhar

I had a Marx motor that wouldn’t run, and I fixed it with almost no effort. If you need to get a Marx motor running again but can’t put a lot of time and effort into it, I’ve developed a quick fix. It’s only temporary, but if you want to run trains today instead of fixing them, it can get you out of a pinch.

You need a screwdriver and one drop of Rail-Zip.

Pull the brush springs out of the brush wells with a pair of tweezers and slide them over to the side. Do this for both brush wells.
In this picture, the commutator is the bit of copper that’s visible in between the wheels. If yours looks like this, the quick fix I describe is less likely to work. If yours is mostly black dust and little copper, there’s a very good chance my quick fix will work.

The trick? Remove the motor from the locomotive (that’s what the screwdriver is for), then look at the commutator. If the commutator is black, there’s an above-average chance this will work. If you’re unfamiliar with electric motors and don’t know what a commutator is, refer to the picture to the right to find it.

Next, apply one drop of Rail-Zip to any visible part of the commutator. Just one drop. Spin the wheels a bit with your hand to distribute the Rail-Zip around a bit.

I let my motor sit for four hours, but you may be able to get by with letting it sit for a few minutes. I would wait at least 15. But when I applied power after letting the commutator soak in Rail-Zip, it came back to life.

If you’re desperate and don’t have any Rail-Zip, you can try a drop of motor oil. Rail-Zip is oil with a bunch of fancy additives and regular motor oil probably won’t have all of them, but it may also work.

Keep in mind this is only a temporary fix. My motor didn’t run because it was too dirty. The oil in the Rail-Zip holds enough of the dirt in suspension to allow the commutator to function the way it’s supposed to function, but eventually, you’ll have to remove the brushplate and clean the commutator the more thorough way. (The instructions for the Marx 999 apply to other Marx motors as well.)

Of course, if this quick fix doesn’t work, clean the commutator the more thorough way. The two things that keep a Marx motor from running are a dirty commutator and a dirty reverse unit. The reverse unit is the trickier repair of the two.

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