Moped Army

What can I do to this stock bike to speed it up a bit? I want to remove the baffle but once I get the nut off the end I'm stuck. Well, really the cap is stuck on the exhaust. I was tapping it with a flathead and a hammer to see if it'll budge but it didn't. Am I doing something wrong?

Also, I hear I can remove a few weights and tighten the springs in the variator but so far I've heard a few methods for that alone. Anybody care to tell me the true story to have this bike haulin a bit more ass without buying shit?