The Expansion Chamber Muffler. This expansion chamber used on a two-stroke cycle engine to enhance its power output by improving its volumetric efficiency. It makes use of the energy left in the burnt exhaust exiting the cylinder to aid the filling of the cylinder for the next cycle. It is the two-stroke equivalent of the tuned pipes (or headers) used on four-stroke cycle engines. provide you with a boost in power and top speed.
This is a direct OEM replacement and will fit either a 48cc or 66cc motorized bicycle and is guaranteed to last.
Overall Ratingcon 1/25/2014got this and had it running for about a year untill it randomly cracked at the top right where it connects the the block then snapped off. other then that good muffler def get it. and its loud but cool.
Overall RatingJoeon 6/25/2013Power OK, but noise level is not as quiet as expected