I was jetting my 08 WR 450 after I installed a FMF 4.1 exhaust (168 main, 48 pilot, 50 leak) and use the needle I got with my AIS removel kit. It sputtered and cut out at about 1/8 through 1/2 throttle. So I ajusted the clip a couple times and it still did it. I removed that needle and put the stock needle back in and it seemed to fix the problem. I was told that the needle with the AIS kit is the same as the YZ needle. Is this true. If not then I want to get a YZ needle because I heard that that will help. I just want to get the most out of my bike.