# Marx 1666 runs but motor gets hot



## David-K (Nov 9, 2014)

Hello, new member here. I have N, HO, and G guage sets, but never any O....
Recently bought a Marx 1666 with smoke unit along with 4 cars and tubular O27 track. After reading many threads on cleaning track, E-unit, and motors, I was able to get the 1666 to run around the oval. But the loco buzzes a bit and after a few minutes the motor frame is hot. The transformer is a Lionel 1053 , 60 watts.
Any ideas on what to check next?

Thanks for sharing,
David


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## Kwikster (Feb 22, 2012)

IMHO, it sounds like a lack of lubrication. I use plain ordinary motor oil 5w-30 for all bearing, bushings and gears except worm gears found on a few locomotives. The wheels should turn freely by hand on that unit, if they don't you have a friction problem. Next up I'd inspect the brushes for wear and be sure the commutator surface is clean. Green scotch-brite pads are the ticket there. Avoid using steel wool, and SoS pads the fibers are bad as the are conductive and get every where.

Carl


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## David-K (Nov 9, 2014)

Carl, thanks for the quick reply. Never used steel wool. Commutator cleaned. I'll give it a lube job and let you know how it comes out.


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## sjm9911 (Dec 20, 2012)

Dave also check your wires to make sure the exposed ends arnt touching the shell or any other metal parts. Some of the insulation on the wires look nicked or stripped back further then nessaccery.


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## T-Man (May 16, 2008)

There are three places to check for a short. First you have a cast shell, place electrical tape on the shell, where the reverse unit has soldered points. If the solder is lumpy it may cause the short. Then check the wire on the center copper pickup. When you depress it makes sure it does not contact the frame. The last is tricky where the wires run down and up into the bottom of the reverse unit. Too long of an unexposed lead will short out on the frame. I have been there and done that!


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## David-K (Nov 9, 2014)

Fyi... the shell is plastic.
Well, gave it lube job and checked the track connections. Noticed that the speed was more consistent but was still buzzing. Added 4 cars and after about 3 minutes the buzzing stopped yea! But now, there is no reverse. Oh well.
Thanks again for the tips.

Wait... just put it back on the tracks and the buzzing is back and reverse works again...


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## njrailer93 (Nov 28, 2011)

What kind of reverse units do they have? Maybe the issue is in the reverse unit causing an excessive current draw?


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## sjm9911 (Dec 20, 2012)

David, the 1666 had metal and plastic shells, they made them for a bunch of years. But the wires can still get pinched and rub on the metal that is there. Look at your first pic, that wire could bounce around hitting the metal. And a little buzzing could be normal. Run it a bit sometimes that works, needs to be broken in again after sitting for years not moving.


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## Yukon Jack (Feb 1, 2014)

First check all the points on T Man's post. If you are still having problems, check to make sure the screw at the bottom end of the brush plate is tight and has clean contact - its the ground. If you still are having problems, it is most likely in the reverse unit. If it is, don't despair - they are easier to overhaul than they look.

FWIW department: Marx made the 1666 with plastic shell, and and the 666 with die cast shell. The 1666 was never made with a die cast shell.


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## Dave Farquhar (Feb 20, 2013)

There are a couple of simple fixes for Marx reverse units that work often enough to be worth trying. 

Sometimes picking up the locomotive and shaking it up and down helps if the solenoid is gummed up a bit. And I have seen them come back to life after running regularly for a while--just run it forward and reverse for at least 10 minutes a day for a few days can really help, for whatever reason.

Since yours acted funny once, then worked fine, the simple fixes may be enough.


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## sjm9911 (Dec 20, 2012)

Yukon Jack said:


> First check all the points on T Man's post. If you are still having problems, check to make sure the screw at the bottom end of the brush plate is tight and has clean contact - its the ground. If you still are having problems, it is most likely in the reverse unit. If it is, don't despair - they are easier to overhaul than they look.
> 
> FWIW department: Marx made the 1666 with plastic shell, and and the 666 with die cast shell. The 1666 was never made with a die cast shell.


Some how mixed it up with the 999. I think Marx used sixes and inverted sixes (nines) to save money!


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## infernisdiem (Nov 12, 2011)

My 1666s and diesel don't like to go into reverse either, I usually have to tap them over the motor to get it to go into reverse, and vise versa. I have not had a buzzing sound, but according to the directions, it is suggested to use a white petroleum lube, I have always used Vaseline with great success, though remember a little goes a very long way, cause if you get to heavy handed, it will grease up the track and wheels, then you have to clean them both up. I haven't had a buzzing sound from my train, but get it from the transformer.


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## Yukon Jack (Feb 1, 2014)

sjm9911 said:


> Some how mixed it up with the 999. I think Marx used sixes and inverted sixes (nines) to save money!


That's always been my theory as well!


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## Handyandy (Feb 14, 2012)

Try some electronic tuner and contact cleaner from Radio Shack. Spray it up into the E-unit from the bottom. Let it drain and try running the loco some more, back and forth a few times and then give it another dose of cleaner.
You may never get rid of the buzz, but functionality should improve quite a bit. I have one 666 that I never could get it to stop buzzing, but it runs just fine.


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## Kwikster (Feb 22, 2012)

Handyandy said:


> Try some electronic tuner and contact cleaner from Radio Shack. Spray it up into the E-unit from the bottom. Let it drain and try running the loco some more, back and forth a few times and then give it another dose of cleaner.
> You may never get rid of the buzz, but functionality should improve quite a bit. I have one 666 that I never could get it to stop buzzing, but it runs just fine.


The buzz is from the A/C current the units run on. You might quiet it down a bit, but not eliminate it. If it was a D/C setup up there'd be no buzz. Without modification the only way to stop the buzz is to lock it into one direction with the e-unit off.

Carl


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## gunrunnerjohn (Nov 10, 2010)

I've used a diode and filter cap to power the E-Unit, makes it totally quiet. There is a remote possibility that you'll magnetize the E-Unit, then you have to do a quick degaussing operation or it'll start sticking.


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## infernisdiem (Nov 12, 2011)

how do you degauss the e-unit in a marx train?


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## gunrunnerjohn (Nov 10, 2010)

I use an old VCR eraser, it kinda' looks like a clothes iron. It'll take the magnetism out of almost anything.


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## DonR (Oct 18, 2012)

It's been a long time since I had a Marx electric train but best I
recall there is a lever (as on Lionel) that disconnects the reverse unit solenoid
so that the loco is 'locked' into whatever direction it was
going when the lever was activated.

If you see this lever, move it to the opposite position and your
loco should again reverse.

If not, see if the solenoid operates when you turn the track
power on and off. The plunger may need cleaning. If it does
you should see it move the electrical contacts. These flip
the AC phasing to the brushes thus reversing the motor.

Don


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## jimtone (Nov 11, 2014)

sjm9911 said:


> David, the 1666 had metal and plastic shells, they made them for a bunch of years. But the wires can still get pinched and rub on the metal that is there. Look at your first pic, that wire could bounce around hitting the metal. And a little buzzing could be normal. Run it a bit sometimes that works, needs to be broken in again after sitting for years not moving.


I've never seen a Marx 1666 with a metal shell? Can't find one on the net either? Are you sure you've seen a 1666 with a metal shell?


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## sjm9911 (Dec 20, 2012)

sjm9911 said:


> Some how mixed it up with the 999. I think Marx used sixes and inverted sixes (nines) to save money!


Read the whole post


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## jimtone (Nov 11, 2014)

I didn't go that far into the threads before wanting to ask what you meant? It's all good!


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