My 88 Johnson 110 on my Ranger 320v recently lost compression on the lower right cylinder. I pulled the head and found pieces of piston ring embedded in the piston crown. There is damage to the cylinder wall and the edge of the exhaust ports also. The motor has been used in fresh water only and usually at around 3000 to 3500 rpm. Is this just an age related failure? The water pump was replaced at the beginning of the season and I have a pressure gauge so I know the engine was getting good water pressure. The other cylinders look fine and had compression of 125 psi each. If I replace the power head I am nervous about damaging the new one. Thanks