If you run the stock muffler and a 20-24oz fuel tank as near as possible to the engine and big fuel tubings everything should be fine. It has a huge carburetor so if you decide to go aftermarket muffler then make sure the engine is getting enough tank pressure and fuel. Regular fuel with 18-20% oil and 5-15% nitro is fine. On a tuned pipe the power of this engine is really scary[sm=thumbup.gif]