they might be half assed , i did pull both carbs out and cleaned out the mains and blew air threw the tube that the main jet sits in and did the same with the Pilot jets ,and the same with what i believe are air jets .pulled the air screw and cleaned it too .
when i put it all back i first made sure the slides came up at the same time and had the air screws set at 1.5 turns out . after a quick warm up I turned the air screws out a quarter turn at a time which took just that first quarter turn out ward . any turns beyond that it fell off peak idle .
I haven't yet . misplaced my compression tester and can not find it right now .
as far as I know this Banshee just has the airbox lid cut off most the way ,FMF SST Headers and FMF powercore 2 tail pipes .
This is my first banshee actually i got it for my wife . i ride dirt bikes most the time.
does not have a cool head and your right about dropping sizes as altitude goes up . most the time here where I live ,your able to get by with opening up air boxes and getting nice pipes with out jetting as factory sets are generally lean at sea level but a bit rich here .