take the boost bottle off.... put an 800 top end on it, dial -a -jets, talk to SLP or fastrax about clutching, and re-do all of your clutching. I would also take the tss-98 secondary off and go with a tss-04 secondary, (some say the 04 isn't as good in the mountains but i have had better luck with them)
Then put the sled on a diet, set up the suspesion better, gear it according to how you ride, high(ER) comp head, and maybe a used SLP SINGLE. Also, clean the exhaust valves and while you are doing all of this, do your self a favor and balence the primary. Thease engines LOVE to eat crank bearings which usualy ends up in a scored top end, and a damaged case/crank.