Tom and George, Man I am having a senior moment, forgot some important stuff.

I am using an APC 9x4 going for a 2 cycle run. The engine was not R/C, I removed the remote N/V and put in the Super Tigre look alike N/V also from Stuka. I wish I had gone with the OS forward mounted N/V like on the 40 & 46, but I was trying to be like Mikie. No going back since the case is drill out for the ST spray bar.

I did reseal the plastic back plate with a heat resistant silicon that I read about on another forum post. I am thinking of getting a metal back plate, gasket set and socket head screw set, from Tower Hobbies, they have them left from the Tower or OS 25 fp's.

I use the stock muffler and have tried it with and without the baffel, but not with muffler pressure.

Another point is that I fly at 5000' altutude, but so did Mike Pratt when his engine ran great.

Tom, I think you set me on to something, my fuel is gettin on in age, from early this year, when I broke in my OS40 and 46 LA's which ran fine. Havent used that fuel since. Right idea, doing one thing at a time, getting a new jug of fuel for this week end.

My employer anounced two weeks ago that they were shutting down the plant where I have worked for 26 years, permenantly, I have two more years till early SS, so I was tring to use all the old fuel I had first, but a guys gotta do what a guys gotta do, unimployment fuel.
Thanks for the brain jump start, Jerry