Check out www.scooterpartsrus.com, pull up the parts for the mt-a1 or a2 find the 47/49cc pimped stock muffler, that exhaust has a little bigger expansion chamber and header pipe, it's about the only pipe that will fit without an extensive amount of modifications, but it may require some at the tail end mount, and you may have to use some heat wrap on the exhaust near the fuel tank.
