if the bike is completly stock beside the filter and are u running the lid or snorkel , without the lid i would say start at 290 mains ans stock pilots and see how it runs if your running the lid with no snorkel 280 mains and lid with snorkel 270 , try the stock pilots ans asdjust the air screws you may or may not have to go to 27.5 on the pilots, and of course these are rough ideas to get you a good startin point, maybe someone with the same setup will chime in