# Marx 666 Smoke Unit Rebuild Tutorial



## Yukon Jack (Feb 1, 2014)

There has been some discussion of the Marx 666/1666 smoke unit. I thought it might be instructive to do a breakdown and rebuild on on of these to give folks a better understanding of the design.

Here is the drive unit from a Marx 666 with smoke unit. This one does not work. 









This shows the underside of the drive unit. Note the black plastic vane that is moved by the motion of the side rods, which are attached to the sliding cross piece.









Smoke unit removed from front of drive assembly. Be careful not to break the tabs on the frame of the motor. Without them, you can not attach the smoke unit. The smoke unit on the 666 also serves as the front motor mount!









Smoke stack cap removed to show the wick.









This shot shows the unit after I have ground off the heads of the rivets holding the two halves together. Separating the halves requires a thin blade to pry them apart - carefully! Shown is the burned out smoke element. Note the gap(no wire) between the two coils. That once was a single piece of wire. Where is passes through the top of the stack is ground. The black plastic piece is the vane, which fans up and down to push the smoke out of the stack. A simple, but elegant design, actually!









All the parts except the element.









Replacement smoke element. These are always available from Robert Grossman, the Marx parts man! Obviously a bit different than Louis Marx's unit.









A bit of careful bending and shaping to fit.









Try it for fit. Note position inside the stack. I basically try to put it in the same position as the original was, and check to make sure the two halves of the case will capture the wires without pulling things out of whack. (That's a technical term....)









A bit of sealant, and the two halves are pressed back together. I use a punch to ping the rivet heads as best can be done, the then clamp the assembly in a vise overnight.









That's it for now. Back later to do the "Smoke Test."


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## tjcruiser (Jan 10, 2010)

Excellent thread / post, Jack! Thanks for documenting things so clearly!

TJ


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## rkenney (Aug 10, 2013)

Very nice pictures! Clearly shows the how the 'puffer' mechanism works. Thanks :smokin:


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## Yukon Jack (Feb 1, 2014)

Unit has been clamped in the vice overnight. This shot shows the bottom with the plastic vane. Note the tab that fits into the cross piece to effect the puffing smoke action.  









The cap has been installed, and sealed to hold it. This also helps with proper airflow. I have connected the unit to a small transformer, and manipulating the plastic vane with my finger.









Houston, we have smoke!

















I hope this has been of interest to those who may need to rebuild a Marx 666/1666 smoker.


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## Big Ed (Jun 16, 2009)

I never saw one of those smoke units before.
Nice repair thread, thanks for posting.:thumbsup:

Be nice to find an old one to fix and just stick it under an old smokestack on the layout.


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## Yukon Jack (Feb 1, 2014)

Thanks, gents.

The next project is to see if I can figure out how (if possible) to replicate the Marx element. I have not been able to come up with the correct ni cad wire, and I suspect the original wick material had a lot of asbestos in it, so not likely to find that! BTW, Anyone taking one of these apart to rebuild, should be cautious in handling and disposing of the old wick material.


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## gunrunnerjohn (Nov 10, 2010)

Interesting smoke unit, never encountered one of those. Great pictures, nice and clear. :thumbsup:


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## carinofranco (Aug 1, 2012)

Yukon Jack said:


> Thanks, gents.
> 
> The next project is to see if I can figure out how (if possible) to replicate the Marx element. I have not been able to come up with the correct ni cad wire, and I suspect the original wick material had a lot of asbestos in it, so not likely to find that! BTW, Anyone taking one of these apart to rebuild, should be cautious in handling and disposing of the old wick material.


I have the Marx repair manual by Julio del Castillo, MD. He also cautions us to be careful with the smoke element as he suspects it is asbestos. He says that even the small amount in the wick is dangerous. he suggests that you keep it soaked in kerosene if you must work with it.


Sent from my iPad using Tapatalk HD


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## gunrunnerjohn (Nov 10, 2010)

Since it's just heat, I would expect that the proper sized wirewound resistor would be a decent substitute. The fiberglass sleeve slipped over the resistor would complete the picture.


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## machinejack (May 5, 2010)

*to old to stop smoking now*

My old 666 Marx that I got in 1956 is still a great smoker. I have worn the thing slap dab out, every bearing, every shaft. I ran it off the table at our last train show and found the only thing holding it together before the crash was old dried out hard oil and grease. I have run ever kind of light machine oil thru it but mostly 3 in 1. Stinks but smoky. Took a not so worn out 1666 motor and pieced them together now I have my old pal back running and smoking again. But I use only store bought fluid now.
I have replaced 4 Post war Lionel's that had quit smoking with the upgrade kit and am very pleased with the results. I have used lamp oil in the Marx for several years without a problem. Problem is I have a Lionel I filled up " from the wrong unlabeled container" with Marvel Mistery Oil I like the smell. Spit and popped several times and now a few little wisps come out. How to clean it out. Would pouring some alcohol and flushing the unit work? I don't think I have baked it yet. Or maybe something stronger.
Thanks
Jack


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## Yukon Jack (Feb 1, 2014)

Jack,

I am no expert on Lionel smoke units, but I suspect one could remove the mystery oil by flushing out the unit with unlubricated electrical contact cleaner. Hold it upside down and spray the contact cleaner into the unit so it will drain. Maybe Gunrunner or some of the Lionel mechanics can chime in.

RogerA


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## jimtone (Nov 11, 2014)

Thanks for the pictorial Yukon Jack! You really made it easy to understand the inner workings of the stack smoker. I'm sure most every stack smoker will come to this at some point in time and you made the repair seam very doable. Again, Thanks!


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## jimtone (Nov 11, 2014)

I was reading another thread today on replacement of a Marx smoker elelment where the guy said he'd use 34 gauge nichrome wire with no iron (non ferrous). I measured the wire thickness on my Marx smoker original element to be 0.79mm or 0.031inch thick which translates to awg 20 gauge. I'm guessing the guy was using a thinner wire to generate more heat with less resistance at less voltage since he was saying he rebuilt his Marx 666 Loco to run around his X-mas tree on 7 volts but was not getting any smoke with the original element. He said he was going to change the element to a 34 gauge nichrome wire with fiberglass wick to produce better smoke with lower power? Am I correct with 20 gauge wire being the original Marx 666/1666 element gauge?


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## jimtone (Nov 11, 2014)

Yukon Jack said:


> Thanks, gents.
> 
> The next project is to see if I can figure out how (if possible) to replicate the Marx element. I have not been able to come up with the correct ni cad wire, and I suspect the original wick material had a lot of asbestos in it, so not likely to find that! BTW, Anyone taking one of these apart to rebuild, should be cautious in handling and disposing of the old wick material.


In your photo with smoker opened, the 20guage nichrome wire is insulated where it passes thru the bottom and makes a 90 elbow up to make four 360 twists and then has a separation of about 3/8" before it continues with four 360 twist and a 90 to pass thru the side at the top of smoker with no insulation. Inside the 360 twists from bottom to top there is an element with black hard insulator material with a VERY THIN nichrome wire inside of it. Is the 20 guage twisted nichrome supposed to have a 3/8" separation in the middle of the rise or is that burned up? I'm guessing it is not burned up or missing but the element that runs from bottom to top piece is the bad spot?


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## balidas (Jun 3, 2011)

Sweet! I have a few of these units myself so this will help getting them back in shape. Thanx!


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## jimtone (Nov 11, 2014)

*smoker unit*

What did you get out of my post that led you to an answer, or perhap it wasn't what I asked about that you were responding to?


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## jimtone (Nov 11, 2014)

When reassembling the 2 halves with automotive sealant, you need to be sure not to any where the top of the element passes thru the rear of the case as it needs to ground to the case.


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## jimtone (Nov 11, 2014)

My computer is struggling with a problem and I was trying to point out not to allow any of the "automotive sealant" to contact the bare wire at the top backside of the smoker because that wire/element is grounding where it passed thru the split casing.


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## Dieseler (Jan 29, 2014)

Did a search and found this thread.
Thanks as i now have a nice Marx working smoke unit once again.


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## Buddur_Bean (Jan 27, 2018)

If my 1666 smokes, but very lightly no matter how much smoke liquid I put in, is there a chance the element is still good and I could clean (unlubricated electric contact cleaner, as suggested in a previous post) to get it to smoke better? Any thoughts, or any tried this with success (just asking since it's been a year+ since cleaning has been suggested)?

I was going to replace the element based on this thread, however, if mine still puts out some smoke I can infer that the wire coil is still somewhat intact and possibly still viable.


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## T-Man (May 16, 2008)

If you want more smoke change it out. I am not a big fan of smoke and usually add a switch to keep them off. It is old and will not get better. 

By the way a great tutorial and the link has been added to smoke unit under the troubleshoot thread by subject.

I recently acquired a 999 with smoke and wondered what I would have to do to fix it. 

It would not surprise me if the modern kit ( Lionel) from Jeff the Train Tender would work.


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## Buddur_Bean (Jan 27, 2018)

T-Man said:


> If you want more smoke change it out. I am not a big fan of smoke and usually add a switch to keep them off. It is old and will not get better.


You got me thinking, T-Man. The smoke I've seen sure looks impressive, but I may regret the room full of smoke after the first run. I don't have a big area and it wouldn't take much to fill it with smoke/fumes. And how my boys have run the train so far, they'll need gas masks for sure. Maybe what smoke I get is simply good enough. 

Love the switch idea to turn on/off the smoke availability. I have lots of bullet butt connectors and typically use them as opposed to soldering whatever wires I need to cut. They'd work as a switch. But do I want tons of smoke when it's on? 

So regarding the potential volume of smoke output with a new heating element, I may be fortunate to only have what smoke I do.


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## Dieseler (Jan 29, 2014)

T-Man said:


> If you want more smoke change it out. I am not a big fan of smoke and usually add a switch to keep them off. It is old and will not get better.
> 
> By the way a great tutorial and the link has been added to smoke unit under the troubleshoot thread by subject.
> 
> ...


T-Man -The one from Jeff works great thats the one i used when i repaired our 666 smoke unit bought them in bulk from Jeff.
Also rebuilt the smoke unit in the Marx 333 engine using Train Tenders works just fine as well.
It would be interesting to see how the smoke unit to your 999 was added, often thought about the Marx 999 and the CV and or Mercury engine having a smoke unit would be a nice feature.


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## T-Man (May 16, 2008)

I got it mixed up. It is a 666 after all.


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## Trainut (Dec 29, 2018)

*Marx 666 Smoke Element Help*

Hello Everyone,
I have seen the thread on repairing the 666 Marx smoker but, I do not know how to connect the batting and element to the existing wires. Would some one please tell me how to do this.
Thank You


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## T-Man (May 16, 2008)

The unit is plastic. One wire goes to the frame. Locate the center roller wire connection on the side. That is where the second wire goes. Add a little slide switch and turn the smoke on/off.


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## WildcatRR (Jul 28, 2013)

Excellent thread. Another one to add to the toolbox. Great job. Well done.


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## jimtone (Nov 11, 2014)

*Marx 1666 chest /side smoker unit*

Is there a sure way for me to test the side smoker unit? I see lots of interests in the stack smoker units but nothing on the side smokers. I've resoldered the wire to the bus but that didn't make any difference. Will it need a continuity test and will it need to be removed to do that test?


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