Need Help with Prop Selection

I have a 21.5' Seawswirl Striper walkaround with a 150 hp Johnson Oceanrunner(1997). The motor runs strong but when it is at WOT throttle I am a little low on the RPM side. When I bought the boat new it came with a 15"x17" aluminum prop. With a full load I run about 4800-4900 RPMs, so I switched to a 15.5"x15" aluminum and my RPMs went to 5000-5100RPMs. Although I did get the RPMs I was looking for I lost 2-4 knots at my cruising and top end speed. I put the 15"x17" back on. This year I am looking to get the Renegade Offshore Prop. I was looking at the 14-1/2" x 17". Do you think this will help? Is this the right size to go from the aluminum 3 blade? What kind of performance can I expect? <br /><br />Thanks for any help you can provide.

Re: Need Help with Prop Selection

Welcome!<br /><br />Switching to a lower pitch did as expected. Your motor is, most likely, mounted somewhat low. I would suspect you could raise the motor to gain both rpm and speed with the 15" diameter prop. You will have to raise the motor when going to the Renegade to take advantage of the technology you are paying for. <br /><br />Good luck!