Scott H.

This forum is awesome. Everyones input is appreciated. I have never run my OS .91 4-stroke so I don't know what to expect power wise. I gather from your post the .91 isn't as strong as I thought. Anyway for a near 9 pound airplane to have good performance a STRONG .90 would be the minimum.

I guess I will have to get a Pitts muffler for the OS 1.08. Will a Pitts muffler fit fully inside the cowl?

Thanks again to everyone for the comments. And a big thanks to RC Universe.

Redcatcher