Recently bought a 2005 zx 50 with 7300km on it. It runs 47mph on the speedo(42 on gps). Confirmed that the CDI has been spliced not sure what else has been done. Checked the pipe and didn't see anything that looked like a restiction. Not sure about the variator washer. The guy I bought it from was the original owner and definitely didn't do any work himself. Carb is clean, battery and plug are about 3 months old. With gear I weigh at max 150 lbs.
So, I would like to get another 5 mph out of the scoot to keep the idiots from breathing down my neck in the 45 mph speed zones. The main reason I bought the bike was for commutes to work in the historic district so I could save on gas and parking so it needs to be reliable. Also don't want to spend more than $50. I'm a little nervous about shaving the boss down and don't have a bench grinder. Can it be done with an angle grinder, belt sander, or dremel? If I screw it up how much is a new one? Thanks in advance.