I just bought a .65 k&b engine off ebay. Will work ok on a 40 size trainer or is it too big? Thanks for the help.

It would be too big for a 40 size trainer. Probably have a hard time balancing the model since it would be nose heavy, and not to mention wont fit in the engine mount if the model came with one. I would get a 40 or 45 for the trainer.

Depends a bit on the trainer, some are bigger than others. The LT-40 is a pretty big airframe compared to some other trainers, I'm pretty sure it could handle the engine. Also, which K&B is it? If it's the "Sportster" line which, I think, was a bushed engine, it wouldn't be that heavy, so it could be ok.

But, in general, I agree that you're better off getting a .60 size trainer airframe to go with that engine. The bigger trainer will be easier to learn on anyway.

Which trainer do you have? It will work just fine with an LT40. They usually need nose weight anyway. I know flyers that use a 60 engine on them to do knife edge. The engine would probable be too much for other trainers such as the Midwest Malibu.[8D]

I'm not exactly sure on the brand trainer I have. It was bought used. The rudder has RT 40T. The original engine (rip) was a .40 fox, I do notice it has extra weights in the engine compartment. As for the engine, it’s a K&B .65 Sportster. Maybe taking the extra weights off it would even out. Thanks for the help.

Max

Could be a Right Trainer? I belive they are made by global and hobby people sells them. Check out the web site

I like 65 Sportsters. However I feel it would be a bad choice for an LT-40 for one reason. The Sportsters like big props. They will swing a 14" easily. You may run out of ground clearance. The power is fine, not too much. Just the bigger props it likes may leave you with too little prop clearance. BTW The 65 Sportster does not like a lot of rpm's. It's a torquer so prop accordingly.

Mark Shuman

I second what Mark says!

These are cheap, but under rated engines (sportsters) Make sure you use (at least) 20% oil content, preferably castor!