Agreed - that's why the initial question - Johnson 140 4 stoke (re-badged Suzuki DF140) that is OEM to boat, 13.8x15 3 blade prop, 2575RL pontoon. 2 passengers, light breeze 21mph top speed. WOT PRM should be 5600-6200. Not a particularly aggressive pitch so I expected to be closer to 6200...