I have a Evo 52NX that is baffeling me. I've owned it for almost a year. Has 15-18 flights on it. I had it in my GP Super Sportster 40 turning a 11x7 perfectly. During the last 4 flights, however. The engine is stalling after about 2-3 min of flight @ 60-70% throttle. I thought it was a fuel system problem and replaced all tubing, checked the tank for seal, and that didn't fix it. I removed the engine, disassembled it, cleaned it, and put it in a brand new edge 540T. New fuel system, new plane same problem. It hits peak rpm perfectly on the ground. I richen it until it drops approximately 400rpm. It transitions nicely up from idle and back.....as soon as it is airborne the clock starts ticking as to when it will stall. The last flight went 2:15 and now I have to repair my new edge 540. I am completely stumped. If anyone can help me before I throw it in the dumpster, I'd appreciate it. Thanks.