Hello Hans,

I'm always interested in seeing some pictures. I have a 120SP in a Top Flite .60 Corsair and a 60SP in a Nitromodels .50 Zero. Both engines perform nicely with big 3-blade props. Just break in your new 90SP as recommended by RCV and you will love it. Break it in on the bench. It will run very rough at first, but you will notice it "smoothing out" as you run it. After you have put about 1 gallon of fuel through it, it should run nice and smooth. Check the tightness of all screws periodically. I would suggest breaking it in with the muffler that came with the engine. That muffler will eventually fail (probably by the time you finish breaking in the engine), and you will have your Genesis muffler for use in your bird.

At this point, I wouldn't consider anything other than and SP for scale applications. I love scale size props and not having to butcher a cowl to make room for the engine.

Good luck with your build,
Joe