Hey guys just seeing if any of you can help me out. I have a 2003 cbr 600rr with about 13,500 miles on it. I have never had one problem with it until the other day when i got a nail in my rear tire. I got a new tire and had it mounted at the local shop. When i got home to put it on i got it back on no problem and started up and about 45 seconds after starting it i started hearing a knocking noise and noticed alot of chain movement when i put it on the stand. The rear is set at right between the notch 3 and 4 and the chain slack is almost a perfect 1.25" so i dont know the problem. I have the service manual and followed it step by step and still no avail. can anyone help me out i would love to get back to riding soon. anything would be appreciated, thanks.......