I have to OS .40LA's - one in an Avistar and one in a TT P-51 Lazy Tiger fun fly. Both engines run great and I have over 100 flights on the Avistar and over 75 on the P-51. The engines like 15% and, once dialed in, will run reliably. The few deadsticks I've had happend when using 10% or less fuel. They are not power-house motors, but reliable for trainers and lighter planes. Just remember the low speed screw is an air-bleed type, so it's opposite of most engines. Left to lean, right to richen your low-end on the .40LA.

My two Tower .46 engines, on the other hand, have been next to useless. I plan to send them both back to Tower as they have a two year warranty which is doubled to four years if you are a Super Savers member. Both of my TH .46's had a lot of deadsticks and are even difficult to get running right on a test stand. I'm no engine expert, but these paperweights had several experienced guys at my field perplexed.