WHAT THE HECK ARE YOU WAITING FOR?! Do it, do it, do it.... DO IT NOW! Just got my JD kit in the mail today and just had to get it installed. I put in the blue needle on clip #4 and the 170 main per the directions. Installation was a snap since I had already pulled out the carb in order to install the ZipTy fuel screw. So, so far I've got a WB E2 exhaust, Zip fuel screw (1 3/4 out), and the JD kit. All I can say is DAMN! After getting it all put back together she started right up. The idle was a tit hair lower, which is fine and the throttle response was WAAAY snappier. You still can't snap it off idle like a two stroke, but I think thats an accelerator pump issue right? I took it around the block and almost crapped myself. It pulled HARD and sounded great. The decel backfire was almost non-existent. In fact, I may just leave the AIS alone. Now, you may just be able to get by by buying a YZ needle and a 170 main and using a flat head to turn out your fuel screw. But, for $20 the fuel screw was no big deal to me and I've heard from the folks here on TT that the JD triple taper needles are well worth the cash. By eye balling the Yami needle and the JD needle, I couldn't tell the difference other than the extra clip positions on the JD. But you guys say there is a difference, I believe you. Anyways, for you '05ers. Don't wait! It should be the first thing you do! You won't regret it.