It doesn't seem to run on DC - just hums and struggles and sparks a little - so I guess it should run on AC, but doesn't. I don't know if it is a matter of current type or something else wrong with the recently re-discoverd set. Can you tell me on which current it should run? Thank you.

I am having a difficult time believing what I am reading.....AC or DC?????
In the late 1940's or even the early 1950's there was nothing that operated on DC except HO scale. A Lionel 1101 engine can be had today for as little as $5.00 or up to $20.00 from my research just now. On all of my Lionel products, there is a small plate that denotes what current is required. Sorry that someone removed it from your equipment.

Hello Don. Actually, Lionel O gauge engines run on ac OR dc. Most if not all postwar ran on AC as you would have to disconnect the whistle or horn if you ran on DC; but you COULD run them on DC.

Your engine has some other problem if it won't work. Better to replace it if you can. It was a low end engine in the cheapest sets.

Hope this helps.

Trainster