I just bought a 98 Hyda sports 20' with a 150 hp johnson ocean runner with a 15 x 17 aluminum prop. The motor only ran 5200 RPM's @ 44 mph and cruised @ 34mph @ 4000 RPM good hole shot jumps right up on plane.I was looking to get a stainless prop and would like to ret my RPMs up a little.I...