I just installed a Gnarly Desert Pipe and Turbine Core 2 muffler on my 2004 KDX 220 I did this in less than 30 minutes removal and installation it wasn't the nightmare job some have had with the FMF pipe. I am very pleased with the performance -still great bottom end very strong mid-range and a good top end not flat like the stock exhaust. I am running stock jetting as recommended by FMF. I thought I wanted a Pro-Circuit pipe but glad I have the FMF! I live north of Atlanta Georgia maybe thats why my setup works so good! :debil: