Old 2" pipe with cheap Cherry Bomb glass pack. The old exhaust flange would bend and leak. New 2.25" pipe with Flowmaster Super "40" series muffler. New exhaust flanges are 3/8" thick with dead soft aluminum gasket.
This is the setup that i have used in my little datto, as the mounts keep ripping as the motor jumps about a bit. Been working great now for about 12 months with little damage to the mount. Better then the three they were lasting.