i put a ct racing pipe with a k&n air filter and open airbox lid and i went from a 130 main to a 152.5 main jet . i am running my ct pipe wide open with no disks awsome sound. I get alot of backfiring and ichecked my plug and it was pretty black. do i need to go up or down with the main or anyother jetting changes. i also got the ct needle but didnt put it in so would i need that. i am also at 10,200 feet elevation wise. the bike seems to run good threw the whole powerband ecept the plugs a liittle black and back fires. Is the 152.5 seem right for my high elevation.

Thanks guys

 

I live in phoenix and run a 170 jet
since you live in a high place a 152 might be to much if your
running rich, and the needle could be some of the problem
if the clip is in the wrong groove

 

Try installing the endcap , mine backfires a little with the endcap off. This will richen your quad up.

Im at about 600 ft. Im runing a 160 MJ stock needle and pilot, about 3 turns out on pilot screw. This jetting was when I had a pipe and filter w/no lid.