What made it even more fun to run was when I updated the reverse unit to a Dallee #400 and put a smoke on/off switch in under the tender.
LOL, the collector in me says: "Oh no, how could you do that?".
But if you want to run your engine, replacing the American Flyer reverse unit with an electronic one makes a lot of sense to me. I have always found the American Flyer units to be finicky.
My 336 doesn't run, I am almost positive that the problem lies in the reversing unit. Hopefully just a little cleaning...........