I think you are on to someting here. 32's on a 1.5 would be way to much unless they were cut down IMO.

How does the boat accelrate with the 1.65s vs the 1.50?

I stand Corrected my Donzi has 1.5 the fountain does have 1.65 I apologize for my ignorance , but even with 1.65 my prop slip is @ 18 percent which still seems a little high?

Understandable. Per the performance report on my friends, it ran just a tick better with the five blades.

My 46 Black Thunder with five blades ran 18% slip, look at the comparable boats with same or similar power and check their top speed, gear ratio, prop pitch and i think you will find your boat is about on for being factory. The gentleman from the Fountain factory are no slouches IMO.

A lot of times you can compensate for too much prop by trimming the drives further out. That will make your slip percentage go up, increase your rpms, but it usually hurts your top speed. What number are you setting for trim at WOT? Also, need to know what number is neutral trim (drive level with boat bottom). With the higher X dimensions Fountain runs, you shouldn't need as much trim. One of the benefits of higher X is that it puts more of the thrust in straight line with the hull with a flatter running boat. Just a thought ...

Do you have your performance report?

I am not sure where you keep the boat but if you are close you can bring the boat to us and we can work with you to dial it in.

We will also be happy to share a few high performance driving tips along the way.