Originally Posted by linkin5

My powercore4 was pretty noisy new not awful but not quiet. I didn't feel the powerbomb (header) affected my jetting at all. Like I said I did the slip-on first without the jets and the bike was fine I didn't check the afr at that point but it was good to go. When I opened up the intake side was when I jetted it, as you could tell it was lean with just the lid off at that point. My bike is an 09 with about 6K hard miles on it and it still runs like new (only better).