Due to having a PBI sprocket that was not machined right, I think my sprocket retainer groove on counter shaft may have been widen just a hair but it's so close to normal I think I am being over critical about possibly shiming (xr650lDave suggestion) the sprocket back JUST a hair. Is there a bit of play in your shaft groove as to the CC sprocket having a bit of side to side movement with it tightened down? In first pic is how it fits with new sprocket if it was bolted tight to new retainer, you can see it is perfectly flush with shaft splines and that is my main question, does yours fit the same way or does it sit back a hair like in picture two? Other ? is the side to side play, your's have some?