I've owned an EVO 46 for over 2 years. While not the best running 46 it has been dependable, biggest complaint is the end of the muffler turning, finally put a 2-56 screw to keep it from turning. I was helping a beginner last weekend with his trainer and EVO 46 and notice bubbles from the remote needle to the carb, but none from the tank to the remote. The engine was surging in flight. Removed limiters and intalled needle on carb cured the problem. Why dont you try that because it eliminates 3 potential places to develop leaks.