YA KNOW i HAVE THE SAME PROB WITH THIS MOTOR.UNTIL I GO INVERTED AND IT DEAD STICKS tHE LOW END NEEDS VERY SMALL MOVEMENTS AND IT LOADS UP ON IDLE BUT. i THINK i AM SUCKING AIR SOMEWERE .WHEN I invert the plane , with it at half throttle most of the time the engine dies like it gets too much fuel or goes to rich but in all other bench test I am running at top notch settings. only when I go inverted.