This ski failed about 10 years ago with cracked cylinder head.Replaced the head a week ago and took it out. Ran within 3 mph of top speed. After about 15 min noticed revs down a bit then failure. Had to limp home at
about 3000 rpm. Took the engine apart today all looked good except shaft between turbo impellers had sheered in half. Is getting oil to cams and oil will emerge from turbo feeds with gravity. Any ideas what could have caused this?