I've been riding these motorbikes for about 9 years now. I have 3 bikes. The biggest problem with these things seems to me is that the exaust pipe and mufflers get plugged up and as a result, loss of power. I clean them out as good as I can, but you can't seem to get into the middle of them. I just tried soaking in carburator cleaner with no results. Mostly I just scrape it out and take a long stiff wire attached to a drill and reem it out a bit. My custom made long "Lake Pipe" (for my 80cc) is so plugged it won't run right. It cost my $200 including the chrome, so I don't just want to put another $20 stock muffler on it. Does anyone know what chemical will eat the crap out of it?