I'm in the breakin stage of my new Magnum 120 Ringed 2-stroke, and I'm concerned about the compression. I only ran the engine for about 4-minutes at a rich half throttle setting, and then shut her down to cool. I noticed though after then run (engine was hot to the touch) I could easily rotate the prop over, and it felt as it actually had less compression than it had when it was new. I have not started it since.

My question is, the compression of "Ringed Piston" engines, does it get better, or worse after the breakin ? I'm afraid I ran the engine to lean during the 4-minutes of run time. It burned around 1/2 of a 12oz tank just in the 4-minutes, and the prop was a Zinger 16x5 wood. Engine was mounted on the plane, held on the ground etc....
Dennis