I recently removed the intake and exhaust restrictors on my sons 2003 kfx 50. I noticed much improved top end, with a slightly better take off. We ran it for a day or two before doing any adjustment to the carb, and actually, while cleaning the air filter, noticed it ran better with more air, so I drilled a few hole in the end cap, which gave us more speed as well. (I have a high performance filter ordered). I just removed the piggy back jet as recommended, but really didn't notice a lot of difference. Right now, it runs great, no sputtering at top speed, as it did before, good response out of corners. I would like to raise the needle and adjust the main jet to get the bikes full potential, but just not sure what I would need to do to keep my air/fuel mix as good as it is now. Any advice is greatly appreciated!!


Also, would an aftermarket exhaust without a jetted carb or bored head be waste?