I set the midrange to exactly what the manual suggested on my .12TR. At first it didn't want to start up but after a bit of fine high and low needs tuning, it finally started to work (and now is a rocket). I've noticed my OS likes a lean setting; I think my low end is about a turn and a half in, and my high end is about a turn and 3/4's out. Also make sure your servo's aren't opening the carb any more than is recommened by OS manual. If you engine is cutting when you give it a little of throttle, then it's probably starving for high end fuel. If it cuts with that "rich" sound where it kind of bogs, you wanna lean out the high end. I would agree with Tennessee that you shouldn't play with the low end needle till you have the high end adjusted correctly. When I started with my OS, I kept it set as the manual suggested. Hope this helps you out.