My 140L has been running good all season. All of a sudden, not so good! First flight of the day the engine runs normal. Second flight it will act as if it is loading up and eventually clear up, but will load up again before I can get it in the air. I've started going through plugs often finding the plug element very black.

High end needle 1.25 out, low end not quite one turn. Regulator is set slightly below flush.

Powermaster DZ30 fuel
APC 16x11 prop
OSF plug.

Any suggestion would be greatly appreciated.

Thanks,
Todd