I have a new 2000 WR which I love and count the days untell my next ride. It has a Pro Circuit T4 pipe and silencer with the stock jetting. There is plenty of power but the motor seems a little rough in the low rpms and alot of back firing. I'm is sc cal and ride sea lev to 3000 feet. Is there anyone out there that is running the same set up or a jetting guru who could help me out. Thanks.