The performance of two-stroke, high specific output engines, is largely dependent on the exhaust system. This paper describes an experimental study on the effect of each of the exhaust pipe sections on the actual engine performance. The exhaust system has been designed with interconnecting flanges that allow the various sections to be bolted together for testing on a dynamometer. This allows numerous combinations of various section designs to be evaluated. In an effort to understand the exact mechanisms involved in the pressure wave action within the engine, several pressure transducers have been located in the intake, crankcase, cylinder and exhaust.