Ok guys I just put a Powerbomb , and a Powercore4 on my WR426. I love it by the way. However this thing is loud. In the description on Fmfracing.com it says you can tune it to be quieter through the end cap. I didnt see anything in the instructions when I got the pipe about this so any help would be appreciated. Also is there any specific jetting that anybody is running besides stock. If anybody has any experience with this exhaust system some knowledge would be appreciated.