You can find OS FP-40s on ebay all the time. I have to force myself not to bid on them. I love the simple air bleed carbs and no bearings to worry about. I put a NIB FP 40 on a Tower Trainer just a few weeks ago. Tower had them for $90 and free shipping. Plus I got $10 off. WooHoo! An $80 dollar airplane that flies really well. It also has heat shrink covering that can be patched with monokote. I know because I already have a couple of patches. I am 3 decades away from needing a trainer but they are so much fun to fly.

I have several plain bearing motors in stock. They just work for me. One of the best I ever owned were the ones sold under the Tower name. I don't know who made them for tower but they started and run just as good as the OS FP engines. Plain bearing engines can be bought cheap because most people turn their noses up at them.