726 smoke unit fire

This "update" is not one I recommend, as there is no reason to do so. The pellet smoke units work just fine with liquid or pellets, and they don't burn up like liquid elements.

I suspect someone tried to "soup it up" with a lower value resistor to get more smoke and got carried away.   The normal liquid conversion obviously doesn't do that with the proper resistor.  Of course, Rob is correct, you can put liquid in the pellet unit and it works, and they're considerably more robust.

I had that same orange glow followed shortly by a fire shooting about an inch out of the stack on a modern (at the time) TMCC engine.  Quite a scary sight.  I reported the problem to Lionel and they had me return it to them for repair.

Earl

With fan driven smoke units with the voltage regulator, that's normally a regulator failure.  It dumps about 10x the power that the smoke unit is designed for into the little space.  The smoke is spectacular, but only for seconds.   I've fixed a few, and I got treated to actually seeing one go up at our club, it was amazing!.  I just wish I could get one to smoke like that when it wasn't on fire.

Yes. I prefer the pellet units myself. I use liquid in them as well, never had any issue. Glad I was home when this happened though. I won't be buying any of them to have in the repair inventory. I had an extra from a cannibalized donor I put in to keep Christmas going. It'll get changed when I get an order put together.

Thanks

I prefer pellet smoke units too. Often I don't bother to fill them. When I do, I use pellets.
The new pellets that are currently made by Trainz work fine.

If you happen to run across any of the pellets or smoke crystals made by K-line some years back, be aware that they do not smell like the original postwar ones. I find their odor to be rather unpleasant.
I have a few bottles, just as a curiosity.

Apparently another party also tried marketing replacement smoke pellets. I've only seen them offered on EBay once. I don't recall the name, but if I saw it again, I think I would recognize it.

Which 726?

Well, it isn't the first. Has the E unit lever through the top. So it didn't have a smoke bulb originally I don't believe. It has the spur geared drive and the weight in it also. I'm addicted to them and have quite a few squirrelled away, some of all the different variations. Working on a rebuild/ repaint now also. This one will have the aluminum stack, which I really like.

I'm on an F3 kick tonight. Have a Texas Special passenger and a Wabash freight running right now. Really pretty. Gonna con my kids into taking some pics or a video so I can share it here. I'm not swift enough.

Anytime a modification/conversion  is done to a smoke unit, make sure the person who does the work knows what he is doing.  Just because something will fit in and work does not say it is safe.   Something like that could burn your house down.  If I recall, that engine smoked ok with pellets.

Well, it isn't the first. Has the E unit lever through the top. So it didn't have a smoke bulb originally I don't believe. It has the spur geared drive and the weight in it also. I'm addicted to them and have quite a few squirrelled away, some of all the different variations

I asked because I am quite fond of 726 and 736 Berkshires myself.
You are correct, the smoke bulb engines did not have an e-unit lever through the roof. The e-unit was controlled through a plug and jack arrangement on the brush plate.

Since it has an e-unit with a lever through the top, it should have worm drive, with only the back set of wheels driven by the motor.

By the way, in the early 1970's Lionel issued a service bulletin on flaming smoke units. Apparently their first liquid smoke units would occasionally ignite the smoke fluid if the locomotive was run at higher voltages with a postwar transformer.

Enjoy your train!

Marty Fitzhenry posted:

Anytime a modification/conversion  is done to a smoke unit, make sure the person who does the work knows what he is doing.  Something like that could burn your house down.  If I recall, that engine smoked ok with pellets.

No doubt. Scary stuff. I am not qualified to do the kind of repairs you do, but I'm going to get a new pellet type and install it myself. I've done many of these simple type. Never can be too careful though. I've even learned my lesson on using shrink tube instead of melting black tape on connections! No joke.

Anyone want to send me something for a rewire??

I think I know the answer.

C W Burfle posted:

Well, it isn't the first. Has the E unit lever through the top. So it didn't have a smoke bulb originally I don't believe. It has the spur geared drive and the weight in it also. I'm addicted to them and have quite a few squirrelled away, some of all the different variations

I asked because I am quite fond of 726 and 736 Berkshires myself.
You are correct, the smoke bulb engines did not have an e-unit lever through the roof. The e-unit was controlled through a plug and jack arrangement on the brush plate.

Since it has an e-unit with a lever through the top, it should have worm drive, with only the back set of wheels driven by the motor.

By the way, in the early 1970's Lionel issued a service bulletin on flaming smoke units. Apparently their first liquid smoke units would occasionally ignite the smoke fluid if the locomotive was run at higher voltages with a postwar transformer.

Enjoy your train!

 

 

 

Yep you're right as usual. I just had the shell off, worm drive. Yes, they are great units. I like them more than both my 773 & 746. 

I'm really getting on an F3 kick though. I've got boxes of units I've picked up and never ran. This is the only time of year I can run trains, so I'm digging  them out and seeing what they feel like doing after some servicing. So far it's been going good.

wonder if the PO used something besides smoke fluid? some guys use kerosene. asking for trouble.

Big trouble.

Wow.  I'm glad I read this.  My track is only 12 inches below my ceiling and on the first floor!!!  The last several days I've been stepping out of the "train room" with the smoke unit running.  Never again.

What GUNRUNNERJOHN said sounds right.

Recently took apart a marx smoke unit that stopped working and tried useing the original wick and rewinding it with traintender pellet wire i had laying around but did not make enough wraps so res was too low .Tested it out of unit and it glowed and went poof in seconds. Yes i know the the wick is probably asbestos and took precaution in doing so.

I enjoy tinkering as i have rewound some of my pellet units counting the wraps and they work great.

But the marx unit had much thinner wire and many wraps, lesson learned.

So in went ttender liquid element easy peasy as they are inexpensive when bought in bulk and work great for lionel postwar and marx.

Its just fun for me.

I enjoy tinkering as i have rewound some of my pellet units counting the wraps and they work great.

I use 34 gauge Nichrome  wire to rewind Lionel pellet type smoke units. It's .0063 inches in diameter, and has a resistance of approximately 16 ohms per foot. I guess a smoke unit takes about a foot.
When I started doing this, the wire was rather hard to find, but it seems to be readily available on EBay these days.

I believe early Lionel heater type smoke units used a shorter piece of lighter wire. But they had issues with short element life, and when to heavier wire. The heavier wire had less resistance, so they had to use a longer piece. I think that is why the redesigned ones have the ceramic piece, to make the wire's path longer.

I bought a engine at a local auction one time ( about 7 years ago) it would barely go like it wasn't getting enough power. I thought maybe my cheap transformer couldn't power it. Seems like it was 1 2026 anyway I said I'll hook the ZW up to it turn the power on and crank it up to about 1/2 way and what I didn't know my smoke unit was shorting, well I got a flame about 2-3 inches straight out of the smoke stack, scared the living you know what out of me. Since then if a engine doesn't seem to want to work a take it apart and see what's going on.