I plan to change my aluminum prop to a stainless model. I currently have a 20ft. Keylargo CC. My understanding is that it is a Hydrosport hull, bought by Keylargo and produced as the Keylargo 2000cc. The motor I chose, is a 2004 150 Yamaha 4 stroke. I have been very happy with the motor. great fuel economy, and power. The aluminum prop that it came with worked very well, but I plan to change it to a stainless model. There isn't an exact 15x17p, but many are from 14.25 to 15.5 at 17p. I can't say what the top RPM is right now, but I will post it if it is really important to answering my question.<br />Do I want to change the pitch if I am happy with the current performence of the boat? I get top speed as 38 to (very seldom) 40mph. I know that I run the motor at 5000 rpm, but I don't remember if I can push it harder than that. Does the brand of prop matter much? How close to the diameter of 15 do I need to be, and what difference would .25 to .5 make in the performence? Thanks for the great help you guys provide.
