One more tip about smoke. There are some very good YouTube videos about fixing modern O Gauge smoke units. If I had a better track record at fixing my own trains, I would study those videos and take a stab at fixing a faulty smoke unit.
Unfortunately, my track record is such that I have, at times, attempted a locomotive repair and made it worse. On the other hand, whenever I fix anything, I'm euphoric. LOL.
I know from reading this Forum extensively for the past 3 years, that many of you are great at fixing your own trains and other's trains. I tip my hat to you. Arnold