Hi Everyone. I'm a near 40 yr old roadracing trackday junkie who occasionally does some adventure riding also on the other 2 wheeled toys. I have a small dirt oval on a pasture and a minimotard track also but recently got bit by the bug to run a little dirtbike out there with other near 40 yr olds. Yep, old guys acting like kids and having great fun. I just picked up a '04 CRF80F and am getting the mod bug, mostly because the 100cc guys are running me over. Have about another $350 to spend and am looking at exhausts. The BBR has my eye but for giggles I uncorked the stock restrictor and so far so good. So let me ask those wiser than myself - I read about opening up the airbox, can someone explain further what's involved? And then if if I put on the BBR pipe and open up the airbox exactly what jetting should I do? Can I adjust the stock carb or should I rejet? Thanks!