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Old 07-14-2007 | 10:25 AM
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Ya guys must be tired of me by now but.Here is my problem. I got a 202 stinger chriscraft. It had a V 6,with a 1:89 alpha on it. Ran 53 on GPS with a 3 bladed 15by25p prop. Had plenty of up trim. Changed motors to a 350 330hp MPI with a arizona speed 360 upgrade.Used alum. manifolds and short stainless risers to keep the weight down. When I ran it with the 3 bladed prop had some speed increase, but would hit the stutter box like right now, did still have some trim up with the button. Needed more prop. So I took a 15 1/2 29 hydromotive prop off my fountain to try. Got more MPH still can hit the 6000 on the stutter box with no problem BUT Now I have almost no trim up and it wants to run bow down. My thoughts are because of the four blades the bigger DIA and the increase of 4 " in pitch( and I can use more) I think the prop is lifting the stern. So I'm thinkin maybe I should change to a shorter gear1:50 run less pitch and be able to get my UP TRIM back and be able to load the motor up more so I don't hit the stutterbox or not as quick. Cause if I go for more pitch seems like the bow might never get up. Thanks Again JOHN

Last edited by Fenderjack; 07-14-2007 at 01:42 PM.
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Old 07-14-2007 | 07:20 PM
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1:50 is the standard ratio drive for the 8 cylinder engine package with most Mercruiser products. You're performance ought to increase exponentially once you've made that ratio change.
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Old 07-16-2007 | 06:08 PM
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The Hydro is definately lifting the stern.

Test with a 30-32 Bravo 1 propeller. These propellers can then be modified to carry the bow much better.

It is something we have been doing for years that Dennis C. taught me a decade ago. Now many prop shops including Merc Racing are refering to as a "BAJA" cup. There is more to it than pounding tip cup into the propeller. It can be customized for the hull. We should of patented it. HEHEHEHEHEHE


This is cheaper than a gear set.
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