Honda did a great job with their OEM pipe but it is a heavy turd compared to any of the other performance pipes out there. There are 36 holes in the baffle that could be opened up to provide a better flow. I have done 12 of the 36 and will run the stock pipe with a 70 kit. I have a 50cc Homeot that I will also use and repack it with fibreglas . the baffle in the OEM can be gently removed from the end of the pipe, if stuck with carbon build up and use some PB Blaster and let it soak.