I'd like my bike to be a little louder. Is it ok to run with no exhaust? Also is there any companies out there that make different pipes for these 80cc engines?
unscrew the screw on the end of muffler,
take the end cap off...might be pretty tight (I used channel-locks on mine)
you can either experiment by drilling holes in the tube connected to the end cap...
or, just cut it off (I left approx 1")
hope that helps