I have a 1975 15' Yar-craft Yankee with a 1975 Mercury 650 3 cyl. 2 stroke engine. The prop is a 4 blade 10 3/4D x 13 1/4P composite prop. I use the boat primarily for fishing, on a large lake (8mi W x 21mi L) I feel this prop is not quite enough prop for this boat/motor combination. The...
