Flying Horse 48cc/66cc/80cc 2-Stroke High Performance Exhaust Gasket &ndash; Gas Bike Muffler Gasket Replacement The High Performance Muffler Gasket works for most 2-stroke bicycle engine kits, whether you're running a 48cc or a 66/80cc engine kit 40mm stud spacing, typical of 2012 and later bicycle engine kits and high performance mufflers To install simply remove your muffler, take off the previous gasket, replace with this gasket, and re-install the muffler Stronger than standard paper muffler gaskets to take higher heat