Smoke Unit

[GpaJer]

I just ordered and received a smoke unit for my engine. I installed it without issue. I added a couple of drops of oil and ran the train and the smoke poured out like I expected. I ran the train until the smoke stopped. A couple of hours later I added more oil and ran the train, but no smoke.
This engine is probably 25 years old. I remember that I had this happen before, when new, I added oil, it smoked, then no more smoke.
Any thoughts on why I get only one "smoke" from the unit and then nothing?

Thanks,
GpaJer


Thanks for the feedback and information.
The engine is a Bachmann HO scale. In reviewing the instructions with the engine, no where does it say to not let the smoke unit run dry. It says to replenish the oil when the smoke stops. The instructions say to only put a few drops of oil at a time in the smoke unit.
This is sure disappointing. I have kept my HO set for over 50 years and now I want to share with my grandsons. You know that they'd get a kick out of the smoking engine.

Thanks again and Merry Christmas!

[Hunt]

The smoke unit heating element burns out without smoke fluid present (i.e. a dry unit).

[Bob_B]

Yes, never let it run dry.
The instructions I have with my smoke generator is top up when the smoke thins out or turn the generator off.
On my engines this can be done remotely or by a physical switch on the loco.

[GG1onFordsDTandI]

You didn't mention what scale train you have, but Im going to assume its Og since smoking Og is most common. The info for other gauges could be a bit different, but Ill bet not much.

In the "reservoir & wire" type smoke units, the wire will glow red hot and burn out, if not kept immersed in fluid to keep it cool. The heat boils/evaporates the liquid which gives you the smoke. The "wound wire and wick" or "electronic resistor and wick" smoke units are a bit more tolerant, but can also be affected by the lack of fluid. Adding a small switch to shut the smoke units off when not wanted, is an easy modification made by many folks.

Over filling can also cause some units to stop smoking for a while too. My 4-4-0 (from another company)(with resistor and wick) is a prime example. If over saturated it wont smoke for days or weeks*, but will slowly come around again as the excess fluid evaporates. Proper smoke fluid is a must! There are different types of fluid not just brands, so check for compatibility.
*Too much liquid cools the unit so much the evaporation rate is slowed to almost ambient temp levels. Put a drop of fluid on your bench and see how many days it takes to evaporate .