I have an 02 WR426. I run the stock exhaust with the pea shooter removed, which makes it really loud but awesome power. I bought the GYTR insert in an attempt to quiet it down, only $40 why not. I am a jetting noob but I realize I probably need to change the jetting to make it work properly. When I tested the insert without any carb modification, I loved how much quieter the bike was but the power was screwed. The bottom end felt like a stock XR400, very sluggish and slow to rev. It had what felt like a misfire in the middle. The top end was still nice, felt the same as before. My question is, will jetting it properly keep the power the same as w/o the insert, or will I be sacrificing some power still?