I've recently decided that it's time to revive my Pacer moped, which has been sadly non-functional since September.
To remedy my previous exhaust problems, I bought a new Biturbo exhaust for it. All I need to figure out now is how to attach the old exhaust pipe (22mm outside diameter) to the new Biturbo muffler (27mm internal diameter, I think). Obviously this needs to be some sort of airtight solid fitting. I've heard of brazing and welding them together...I just need to figure out how to shim the difference in diameters out before I can attach them together.
Any suggestions, besides getting a custom pipe made?