Evinrude 150 prop selection

Hey guys,
Over the winter I rebuilt a 1973 Mako 19 and then bought a 1998 Evinrude Ocean Pro 150 hp. It seems like boat should move a little faster with this power. With a 15x15 aluminum prop, I could achieve the max rpm at 5700 but only 34 mph. With a stainless 15x17 prop which is what I am sticking with for the time being, I got 5200 rpm and about 42 mph. With a 14.5x19 aluminum prop, I only got 4800 rpm and didn't get to check the speed. I am thinking a 15x16 prop would be perfect for rpms but I don't wanna loose anymore speed. I would think this boat with a 150 should be hitting the high 40's low 50's easily. I did replace the deck completely with 3/4 plywood and replaced the transom and it has probably more glass on it than before so the boat may be a little heavier. Still I would think I could get more speed. The engine is moved up 2 holes and I may need to go one more but there really isn't much spray. Thanks for any ideas or tests I anyone can think of. Here is a link to the boat running with the 15x17

http://s1212.photobucket.com/albums/...t=IMG_1026.mp4

Re: Evinrude 150 prop selection

Since your WOT rpm range is 4500-5500, and power is rated at 5000 rpm; it looks like you're right there at 5200.

Other 19 foot CC boat run in a similar speed range with a 150.

Re: Evinrude 150 prop selection

Alright, no magic props out there? Anything anyone has experienced to get just a few more rpms?

Re: Evinrude 150 prop selection

Every inch of pitch will gain(or lose) 150-200 rpm.

Make your adjustments based on that.

You might gain a little by raising the engine.

Re: Evinrude 150 prop selection

So would a 15x16 theoretically be a good choice for me? It would put me in the 53-5400 rpm range which is exactly where I wanna be. Is there one out there with a design that would achieve those RPMs and gain a little or at least keep the same top speed?