Weird Noise (Maybe Paranoid)

I drilled my pips\es out about 2000 miles ago, total of 4900 miles, and it feels like maybe i have lost some power. When i accelerate there seems to be a "knocking" coming from the motor that is not there when idleing or just cruising at a constant speed. I even leaned down to listen to the motor on the interstate and it is purring like a kitten at 80. Could my bike be running lean/rich? If so how do i tell and adjust the carb? If i am just being paranoid and the engineis supposed to be making noise then just shoot me.

Thanks for your help,
Mark