Just got my engine back after having the piston and sleeve replaced and went to the field to break it in. Ran a tank through it adjusting needles and letting it cool every couple minutes. Runs great but I noticed that as it heated up it lost compression and eventually died unless I played with the throttle a bit (up and down). Am I correct to think this is normal in that the piston and sleeve are still seating themselves and the compression will improve as it breaks in further? It is fine when cool.

Thanks!