ORIGINAL: ScienceisCool
When the engine is hot it is very easy to turn the prop all the way around with just a little resistance going through compression. When it is cool it takes more force to push though compression.
After running for a few minutes it becomes unstable, in that the rpms go up and down without touching the throttle (mostly down). At WOT you can hear the rpms slowly drop and if you let it go it will die.
The compression is normal.
The rpm description sounds like it is running lean.
When you turn the high speed needle counter clockwise the engine should slow down.... does it ?
If it slows down will it run at wide open throttle for the whole tank of fuel ?