This is really interesting.

I fly at sea level in southern CA so it is usually pretty warm, but nothing extreme. I am using Powermaster YS20/20 fuel and the plane weighs in at 6.5 lbs dry, so probably a tad over 7 wet.

The prop I have been using is a Topflight 14-6 wood with an OS F plug. The 9,500 rpms on the ground should be plenty of power, I could lean it out and try to get ten, but the engine still has only about an hour to an hour and a half on it.

There is the possibility that the plane is losing power in the air, but I don't know how to assess that. Any suggestions.

The plane should be out of sight.