I just purchased a new to me 20' pontoon with a 40hp Mercury outboard. I believe the year is 1995, it's a 4 cylinder and the prop is pretty chewed up, I can't read any numbers. I should add I don't have a tach, unknown optimal RPM. What would be the diameter and a good pitch prop to buy as a replacement? Would a 4 blade be better than 3? Any help would be appreciated. Thanks.
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