I just picked up an '01 WR426 this week to compliment my '02 YZ426, so I'm new to the WR but not the 426. It has a lot of toys thanks to the previous owner. Complete FMF exhaust boysen excelerator, dynojet jetting for high altitude among other non-engine-related parts. He also had the cam shifted 5 degrees in order to "make it run more like a YZ." The WR has an FMF power bomb header and powercore 4 silencer. Now, I'm not the one to complain about a loud sweet sounding exhaust but this thing is pushing it. My YZ has the same powercore 4 with stock header only it is quieter. I checked to make sure it was installed properly and sealed and it is. Is there something I can do to quiet it down just a little? I have also noticed less of a snap in the engine over the YZ. It is much harder to get the front end off the ground on the WR. Is there a difference in the engines that would answer this? I understand the difference in transmission, close as opposed to wide. And lastly, Does shifting the cam 5 degrees really do anything for the power? That's what I'm looking for here is the power of my YZ in my WR. It's almost there. It doesn't seem too much to ask.