I have an 04 ltz 400 bored out to a 440 with an hmf silencer and a powerbomb header pipe. Pretty sure it's jetting as it wont idle right and it's popping on decel a lot. Any ideas on what jetting should be for this setup. I ride around 20ft to 600ft above sea level. It is a stock carburetor. Let me know if you guys want more info.