I have a 2006 YZ450F, finally parted with the 03 and got one off the showroom floor. The only problem with the bike is the jetting. From the first time I rode it, it would pop on decal, so I adjusted the fuel screw, seemed to fix it, but still seemed like the bike was running lean. Now I put a pro circuit T-4 on and fired her up and she was lightly smoking, black smoke and when I would hit the gas a cloud of black smoke would shoot out and a few sparks. So I rode it up and down the road doing wheelies, seemed to ride great, but when I put it back in the garage and turned it off, the tail pipe was smoking and it stunk, seemed like it was really hot. So im guessing it is the jetting that is off? Anyway I am not so good at jetting or messing with carbs, so im here for help, anyone re jet their 06 and if so have any pointers or settings that they could share with me or give me directions on what I need to do would be great. Any help would be greatly appreciated. I have no clue what the stock jetting is, the bike came with two extra jets, would those be good enough, or do I need to buy a jet kit? I just hate digging into the carb, always feel like I am going to F something up. Anyways, here are a few pics of the new ride. Black warp 9 wheels, oversize spokes, chrome hubs, pro circuit t-4 exhaust, carbon fiber fork guards, aluminum case saver, aluminum rear brake shark fin, ASV levers, Renthal gold o ring chain, black Renthal sprocket. More to come.