I maidened my new Stinger II a couple of weeks ago. OS .55ax with Bison Pitts muffler, would only idle about 8 seconds and die. Went out this past week and got in two more flights. Switched from an os 8 plug to an os 6. idle much better. I am running a little on the rich side, but this thing screams! I am really excited with the way this plane flys. Awesome! Smokin top speed, then cruise around at 1/4 throttle. Lands easy! The last time I got this excited with a plane was when I switched from my trainer to a GP Big Stik. Now my big stik is my warm up plane and my Stinger II is my go to plane. I think I will buy another one just to have it in reserve. This plane is a blast!