Here's the deal, this thing runs like a monster, on the ground at least. I can crank it up to full, throttle it up and down, and hold the plane straight up, and it seems to run perfect. Put the thing in the air, and it won't do it, starts chugging, and eventually dies. The manuever that it seems to hate the most is when I fly inverted, give it full down elevator (like I'm going into a outside loop) until it's vertical and throttle up. Dies everytime. It is a relatively new engine, should I just be patient and let it break in more? Should I try blocking off one of the exaust ports? (I have a bisson pitts) Try out the perry carb? I dunno, I'm new with the big two strokes... any help would be greatly appreciated. Thanks.