Don't mess with it, I'm returning mine to stock today. Runs like crap in my part of the country, there may be alot of good advice on here but this was not something worth doing for me. Ran terrific before but I was trying to make a four stroke into a two. Unless your running lean I wouldn't waste your time or money. I bought my jet from boats.net and a friend who owns a bike shop gave me the shims, they are going in the trash after this experiment. As far as the air mixture screw there is a plug with a hole in it, all you need to do is turn a screw into it and pop it right out. Mine is an 06 also, good luck.