As the title states, Im stumped. Took my freshly rebuilt Yz 250 out to the track saturday filled it up with fresh mix 50/50 pump/race fuel and Amsoil Dominator mixed at 40:1 and put in a good 30 mins of track time. Took a 30 min break and went back out and ran out of fuel after 5 mins. Thats way too fast, seeing as I took my 08 yz250 to get a couple laps in on the race bike as well and let my buddy ride my 03 yz 250 and got two full 30 min runs out of both of them on the stock tanks with the same premix. Pretty much stock motor other than port and polish, and squish set which is also done on all 3 bikes. Ive went over carb settings 3 times and everything is well within spec. Theres no fuel leaking from the over flow and plug chops show my jetting to be a tad lean on the main but nothing that cant be cured by goin up one step. Im no pro so theres no way Im pushing the bike that hard to run that much fuel through the bike in an hour. Anyone have any ideas?