Hey guys i am new to this site... I have a 2009 YFZ450R, was riding it a few months ago and the chain popped off, put it back on, started up the quad and it was running fine, i put in in gear and started moving and it started knocking, stopped, put it in neutral, and it stopped, starting moving again, and it started knocking again, put it in neutral then it was knocking the whole time. I pulled the clutch plates out and tried spinning the inner clutch hub, and it only spun about 3/4 of a turn then got tight. I can spin it past this point but it gets hung up again in the same spot. i am lost. I am not new to working on these engines, although the only thing i have ever had to do was top ends on them, so the bottom end is something new to me. My cousin used to be a Pro-Am atv racer and he built his own motors. So i will have him help me do it. Just want a general idea of where to head on this as of your stand point and thoughts on this issue.

Thank you much!
-Chase