My '93 120hp locked up this afternoon...going down the lake...running just fine at about 4000rpm...had just gone to WOT and about 3 seconds later it started making this awful knocking sound and about 2 seconds after that it quit. I'm guessing a rod came loose or broke...but again Im guessing...wont turn over by hand with spark plugs out. Does anybody have any recommendations for rebuilding/remanufacturing?