Edit: The Sick BP Aluminum exhaust gasket is good, if using a stock muffler. Its too thin to work well with the mower muffler. I'm using the cork gaskets.
I think monsterscooterparts has pocketbike or scooter mufflers that will fit this engine, probably better quality and quieter.
When I made this second muffler for the bike, I cut the cooling fins just a little so I didn't have to bend up the muffler. This seals better now.
Edit: Don't drill out any of the holes and use the supplied exhaust director chute and screw that goes in the center hole. I blew up the last engine. This one has some backpressure and works a lot better, and not so killer decibel levels. :jester:
