Marx won't run...

Check reverse unit drum for dirt or a broken wire.

You can bypass the reverse unit for forward only operation.

how would i go about this? would i have to remove the wheels and take the frame apart to dissect the drum? i'm not too concerned about a reverse unit anyhow (will be going around the christmas tree) and how would i bypass it?

Do the wheels turn easily by hand?  If not, you may have a gear teeth problem or the armature is not seated right, making the little main drive gear catch.  If they spin all right, check all over for broken connections. 

okay... yes, the wheels turn very easily by hand...

weird thing is... i put just the motor, no body on my main layout with my cw-80 and it zips back and forth like a bat outta he-ll.

put it back on my test track with the zw and nothing again...

One important thing with those Lionel transformers.  Don't be givin' the little thing more than 12 volts.  That's all they're designed to handle.  I sure can't explain why CW-80 works and ZW doesn't, but if you're saying that putting the shell on causes it to not work, some metal on the shell must be shorting out on the motor somewhere.

body or no body, it'll pull it's 4 cars around the layout no problem, however the cw-80's blinky overpower light is on all the time... so maybe it's a short someplace in the motor or the e-unit?

If the store where you bought the engine has a track, I would take it back and ask to see it run again, for comparison.  If it acts up, tell the man, "Hey this isn't working."  But I'm almost wondering if your problem may be somewhere in your track or transformers.

i would but it's a 4 hour drive away. i'm pretty sure i haven't broken anything and their policy on marx stuff is "no returns"

Basics, which you have already done some

1: Make sure everything turns easily by hand.

2; Make sure the screw at the base of the brush plate is tight. This is the ground and a common gremlin for Marx motors

3; Being as it runs on one set up and not another, make sure the drivers are clean, then check the center rail pick up. Make sure there is good travel and spring tension on the sliding shoe.

4; Being as it behaves differently out of the shell, line the boiler near where the reverse unit would be with electrical tape. If that helps, find out what is touching. This is also a common problem, but mostly on 666's.

5: How worn are the brushes? The spring may not be able to exert enough pressure on the brush.

6; Spray inside the reverse unit with contact cleaner, then shake so the plunger moves around. Do this a couple of times followed by a last good shot to flush out any debris loosened up.

As for the flashing light on the CW80, it may not have anything to do with the motor. I have the exact issue with one of my CW80's. It just does not like Marx motors but they work great on other transformers.

Marx does not use a drum in the e-unit. They have a rocker moved by the up and down motion of the plunger inside the coil. Except some prewar motors, there is no factory provided method to deactivate the e-unit. You can rewire it to bypass the e-unit or jam the rod that moves the rocker. This is the simple & easily reversible method I use when I'm too lazy to take apart the e-unit and fix it correctly

Steve

Just for the heck of it check and make sure the draw bar isn't shorting on the center rail. Since the bar is attached to the boiler shell this would not be an issue with the body off.

Jim McClenin

steve: everything you've listed for me (with great thanks) i've gone through. the brushes are near new, the drivers and shoe are clean and good, the shell i've lined with tape to no result and i've jammed the e-unit rod with a piece of toothpick. everything works fine on my main layout with the cw-80. thing is i'd like to hook this up to a little blue lionel trainmaster transformer for the tree... no dice

hmm... i dunno what i did or how it happened, but the little blue transformer will run the marx locomotive just fine... problem solved i guess...

thanks to everyone for pitching in your two bits on this!

 I was gonna ask " how does a Marx not run ? " 

that's what i was wondering myself!

As the man said, "The only rare Marx engine is one that doesn't run!"