The KTM factory got the 2009 85sx motor wrong. They had fitted a conrod that had a too big diamater pin resuting in the bearing going too fast and heating up, this meant that the big end kept on seizing. It was seized when we got the bike (cheap buy!) but seized shortly after I fixed it. I did some digging and found the issue. So I ended up buying a 2012 complete crank. That solved the issue!