Hi Jerry,

Thanks for the input. I also sealed the carb and back plate as well as tightening the head last night. I still had the problem today before inserting the baffle.

It was obvious when I looked at the exhaust pressure line that it was not pressurizing the tank.

When I dissassembled the muffler, there was absolutely nothing inside except the long retaining screw. Once I inserted the baffle, the engine worked great at all orientations, and with lots of power.

Can you tell me the diameter of the exhaust hole in your muffler, and is there any baffles etc. inside your muffler?

I'm curious to find out why some of these engines work fine and others don't.

Thanks for your help.

Fly4Fun,

Wayne Miller