I just picked up my 2008 yz450f limited edition two days ago... I took it out and it has pretty good power... Well for a 155 pound rider like me... It ran just great for the first 20 minutes or so... Then It got really hot... I live in vegas so it's 110 degrees but Whenever i'd hit a bump or two it would bog and almost die... Then I took it through the whoops and it died... Keep in mind I was only in second gear half throttle though so it's not like i was beating the hekk out of it before it's broken in... I'm coming off of my 250 two stroke so i'm kinda confused... Some of my friends say that it's just jetting but i am not sure and was wonderin if you have any tips????