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With my Super Sport 15 and F70 combination, I am currently mounted 2 holes up (one below the highest the motor can go). Performance is good and mileage is outstanding, but I'm still a little sensitive to porpoising - mostly boat in the ocean and it's never all that calm, and even modest amounts of trim tend to get me bouncing pretty good.

I'm thinking of trying to move up that last hole, in an effort to improve that aspect of performance - running a Stiletto Advantage so should have plenty of grip. Has anyone tried setting the motor all the way up on their 15? And if so, how did you like the results?

For reference, I did try a 5" setback jackplate and had the motor raised pretty high with it - ran pretty well, but it still porpoised. The extra length and height created some storage challenges, and there was also significantly more exhaust noise at idle. And since Mrs. Carom likes to cruise along gently most of the time, I took it off.

Tim

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Hi Tim,
When I was running my F70 on my 1984 15' CC, it was 3 holes up using a Stiletto/Turbo 15" pitch, as I recall. It performed great, but the boat was not too comfortable for my frame.

Dennis

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Thanks Dennis, just what I needed to know, as I have that same prop. I hear you about the frame - I raised my interior 2 inches, and it still feels small.

Thanks for the height info - I will give it a try!

Tim

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Shift some weight forward to counter the porpoising.

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Tim, I tried everything with the stiletto prop. Different pitches and engine height and eventually with the help of Mike at Skips propeller here in Charleston and Wayne Baker "Bake" here on WhalerCentral, I finally narrowed it down to two holes up and a 13x17 turbo prop. Mind you with the help of a hydrafoil, it jumps right up on plane with five in the boat, corners nicely and handles excellent when the harbor is having one of its tantrums, just me and another in the last scenario. I'm not saying don't use the Stiletto, I'm saying that three holes up in my opinion can be too high. Also, I noticed that the 15 pitch would keep my boat from porposing because it would never get the hull up on the "pad" planed off all the way. The 17 seemed to be the happy medium with two holes up.

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I did have weight shifted forward as well. I had a 14gal gas tank right under the seat (this was the only tank), and the battery was moved to the console. With this setup, I don't recall it porpoising. It got to 42 or 43 MPH, measured using handheld GPS, but not validated by reversing course & averaging.

Dennis

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I'm running 2 holes up with a 50hp 2 stroke and a Solas New Saturn Stainless 13 pitch prop. I tried 3 holes up and unless the trim was all the way down I got aeration while accelerating onto the plane. I also found there was not enough bow lift in this configuration.

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Huck, I am not sure I understand your point. I am not surprised that the 15 was not enough pitch for your two-stroke 70 - I previously had an 1989 Johnson 70 on my boat, and the 13.25x17 Turbo worked really well, at two holes up.

But I do appreciate your comments and others as to whether putting the motor all the way up will work or not - some have had good luck and others not so it looks like I will have to try it and see.

Tim