well got my 500 back together with moose reed spacer. only now i have a knocking sound at 1/4 throttle, like large rocks in cylinder, when on and off throttle, plus that anoying surging on decell is getting on my nerves. i checked for an air leak and found none. have stock jetting but my air screw is at 1 turn out to get rid of throttle bog when snapping throttle open. some say this is a normal 500 thing, but im not buying that.