I have a 2002. As I was attempting the utbdr, everything was going great. Day 4 a knocking sound started at idle and while I was riding. I continued to ride. The bike ended up bogging out and wouldn't go over 40mph. After towing it back home. Tore the bike apart. Thought it was the cam. Replaced the cam. Had work done on all 4 valves after getting a compression test. So the top end is in great shape now. Started it up and the knocking is still the same. What in the bottom end could it be? My buddy suggested the crank. I'm not the best with bikes. Any advice would help.