I beg to differ about the exhaust deflector. An exhaust deflector can cause a change in the back pressure of the engine. Some engines won't tolerate much added to the muffler...even ones with a very small curve. Since the Hobbico NexSTAR doesn't come with an exhaust deflector, one must have been added. As was stated above, this does change the pressure relationship of the muffler and tank. Even when properly-leaned, an exhaust deflector can add just enough additional back pressure that the engine will gradually overheat and then quit. Most of the time, though, no damage happens to the engine.

The cone inside the muffler should be oriented with the wide part forward, coning in towards the rear.