Last year I bought a used 20 ft. pontoon, with a 1995 40 h.p. Mariner on it. It came with a 10 3/8" X 13P prop. I need to get a new prop, and I'm not sure if I should go to a 4 blade. If I do, what pitch and diameter. What are the advantages/disadvantages. I'd like a little more top end...
