Well I finally timed my 02 wr426 to yz specs. And WOW what a difference. It is much snappier now with less engine braking, feels more 2 strokish. I like it! The biggest difference for me was the less engine braking, I can coast much easier now without having to constantly throttle it. I haven't tried it on any gnarly single track yet, so I'm not sure if it will be good for that type of riding, but for faster open trails it absolutely rips!