I’m a novice flying a Great Planes PT-40 with an O.S. FS-52 four stroke engine that has about two hours on it, so it’s broken in. The engine quits just after finishing an aileron roll. It handles loops and stalls OK. On the ground the engine runs OK when the plane is pointed straight up and when its inverted. What could be the cause of the engine quitting after finishing an aileron roll?