Got one in the other day with the owner complaining about the engine won't spin over. The boat had been sitting for about a year and ran good before parking. Crossflow 200 Neverrude. The flywheel would rotate clockwise/counterclockwise but would stop just before making a complete revolution. Dropped lower to make sure it wasn't the problem. Pulled all six side covers and pistons looked new and clean. Took a magic marker and marked all six pistons to see which ones stopped at the same position each revolution. #1 appeared to be the problem with seizing at TDC. Removed the head and corrosion had built up between the cylinder wall and the cylinder liner causing the the steel liner to swell up. The cylinder liner was completely distorted and out of round and you could see by the blowby marks that this had started years ago. Had the owner to come by and I had a brain fizzle. Maybe if I heated the outside alum cylinder wall, the alum would relax and the steel cylinder wall would flex back into shape. Didn't happen. Due to the age, engine is junk now. In 30 something years, never seen this happen before.
