Yam. 2002, suv 1200; was running fine but heard a slight upper cyl. noise. Engine stopped, retightened loose battery connection, tried to jump start, towed to port. I pulled starter, spun o.k.. Could impeller stuck? as i drove through a lot of seaweed and sand. Is the only test to pull the head? I pulled plugs ,rear looks terrible but not collapsed, Is ther a step by step on pulling?? ,and a good place to get shop manuals? Thanks, Steve S.