I have one dead cylinder on my 20 hp Briggs V-twin engine. No compression on one cylinder. It starts and runs but lacks power. Does not make any noise. I pulled the plugs to check for compression and one cylinder has 150 lbs and the other one has zero. I inserted a wooden dowel into the bad cylinder and the piston does not move when I turn the crank. I figure the cap that holds the rod came off and is in the bottom of the pan. What do you guys think? I need that repair manual so if anyone can help me find one online I would be grateful. Thanks!