Well I changed it from A 389 r4 to a 389 r6 and boy did that make a difference it idles perfectly now it does not lean idle very long if at all after a long hard run I am very happy with it. Jerry hit this one right on the head. I should also say that I have many two-stroke high-performance quads and the zilla seems to be about the most well tuned of all of them. It is my only race fuel machine that starts when it is below 30° without heat and it starts much easier than my Hondas do. Thank you all for helping me get this quad dialed in for the cold.