I guess I didn't mention that I run without the Airbox cover. I have not rejetted though. Was told by know-it-all type guy at the dealer that I didn't need to. Plus they wanted $9.95 for a stinking jet!! He said here in MN at 700ft with temps one day at 60 and the next at 90 (which is true) not to worry about the main jet. He said move needle clip up one and that's about it.
Maybe I will have to get the pipe. One last question. Can the stock unit be called a silencer, or is it a spark arrestor? Or are they the same thing? I'm basically looking for a little more throttle response with ever so slightly greater ability to pull wheelies. It only pulls them in 2nd and sometimes in 3rd. Could be my riding style too, but I was on an RM 250 and it wheelied for me too much. I don't want that much, just a little more than I've got. The 250 felt too hairy on the trails I ride, but my 220 is lacking just a tiny bit. Maybe a larger rear sprocket, or 12 tooth front?????