alot of things depend on jetting.... a stock banshee motor with no leaks, in the summer time, with pipes, aftermarket air filter in air box with no lid and anywhere around 1500ft above sea level to sea level with stock carbs a 280 main jet should get you pretty damn close if not dead on. a proper plug chop will confirm it though and is the best way to tell how your jetting is. more air ( after market air filter, pipes, no lid on air box ect) = more fuel needed ( bigger main jets and sometimes pilots too) depending on elevation as stated above i would keep the stock needle on middle clip and throw 280 mains in and the 27.5 pilots. in the winter your gonna have to bump up the mains to around 300.
here... look at alot of these set ups. if your not sure of your elevation goggle it.
oh and dont forget to learn to use the seach function on this forum
http://bansheehq.com/forums/index.php?showtopic=99361&st=180