I put the full FMF exhaust, removed the snorkel, and Boysen reeds on my 2001. I never could get the jetting right to make me happy. As a last ditch effort, I went back to the Kawi reeds, and got it jetted right with no trouble. Now it revs out good and lugs good too. I can't imagine really needing a fly wheel weight once a KDX is dialed in right.