I own a 350 Warrior with a K&N filter, FMF Q4 exhuast w/power bomb header. My quad was ripping so I was hesitant to change the jet. But, FMF recommended to run the kit, so I did. After reading the informative yet slightly complicated trouble shooting and jet selection page. I installed the needle, main jet, and fuel mix adjustment screw which was very easy(installation directions was great). I notice my stock jet is #145, so I install the recommended jet #148, slightly larger. But when I ran it, at mid throttle it bogged and couldn't run great. I was very surprise, so I changed the jet to a larger #150, and it still bogged. I then decided to install the stock jet back in just to see what would happen and it started to ripp again. The needle setting was the only thing that I found useful in the kit. I did compare the needles and the FMF was slighter more tapered. If you are planning to continue your build or mod, this kit would be great because it comes with many jet sizes for your mod needs. The kit does include #146 which is a size in between the stock and recommended #148(didn't work) that i haven't tried yet, but the stock jet runs SUPER, so I'm gonna leave it until I feel like taking out the carb again. Also, I'm gonna get a CDI with higher RPM to see if that would make a difference. But, I will say that with the jet changes.. my quad does redline a little faster, because I do notice that I have to shift 1st and 2nd gear faster, so acceleration did improve. I also can easily wheelie my quad now, low end seems more responseful. That why I'm giving it a 4 star.