24ft pontoon w/2 23" tubes w/2005 Yamaha 150hp 4 stroke, approx. 3000lbs. w/ 2people and full tank. Final drive ratio is 2.0. Started with 14 3/4 x 17" prop, was getting 4700 to 4800 @ wot, approx. 27mph. Switched to 15 1/4 x 15" and got expected 4000rpm increase to 5100 to 5200 @ wot, approx...
