My top end looked like that last year. I had a cam chain roller wear out and tear to peices and let the chain move around alot and ate up some aluminum........ I pulled the head and jugs and oil pan and pump blew air through the bottom end. Clean the top end and jugs and put'r back together. Runs like a top still..... no worries.......... Guess the real test will be 2000 miles in one weekend for the wchcm at the end of july lol. But I've put a ton of miles on her since that rebuild already.