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Old 09-19-2016 | 11:14 AM
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My 89 311 has 330hp and I bought a set of hydromotive 24 pitch 4 blades and put them on before I ever ran the boat. So wide open full of fuel it only turns 4000 rpm...but once it gets lighter on fuel I can turn the motors too around 4200. Problem is once I start trimming out it had a horrible porpoise...I guess either the boat just isn't fast enough to run through the bouncing or the props are causing it. Who has ran bravos on their boat? Any issues with them? Also boat only runs 60mph wide open. Thinking I may need to drop to a 22 pitch. Problem is I love the cruise speed with the 24s and it comes on plane with no issues...
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Old 09-19-2016 | 11:30 AM
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If you porpoise while trimming out, I would just trim back in a bit until it stops . . .

You also might be a little over propped, since your RPM is not quite up to spec.
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Old 09-19-2016 | 06:38 PM
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It will start to hop at like 2-3 on the indicators..
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Old 09-19-2016 | 10:53 PM
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My 292 does the same thing. I just tested some hydro 24's on mine so see if I would lose the porpoise but nope- same as the bravo's. The Mirages porpoised the least of all the props I've tested. Now the big difference is I've got 1300 hp now, so once I hit 55 I start trimming up. Then the boat gets loose and really feels great. At 60 the boat is just starting to come to life. find a set of 23 Mirages and test them out. Get a set of non-pluses. Your hull will like them better than the Mirage Plus props. That should allow to you get close to the 4500 rpm mark. You are over propped now.
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Old 09-20-2016 | 07:30 AM
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I feel like the boat needs way more tail lift then a 3 blade can provide. It rides bow high now with 4 blades and still drags the tail..
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Old 09-22-2016 | 09:11 PM
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Try the 22's ... how many hrs on the 330's? Those motors aren't real strong to begin with ...
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Old 09-23-2016 | 04:36 PM
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They do have 700hrs on them. But the fact that it still runs 60 turning 24s they still seem strong...
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Old 09-23-2016 | 06:06 PM
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Try the 23's as stated ....you need to be at 4600-4800 ... my 89 311 came with 23's...
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Old 09-23-2016 | 06:40 PM
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Originally Posted by stlliberator
Problem is I love the cruise speed with the 24s and it comes on plane with no issues...
Most everyone likes the cruise speed of props that are too big.

It's like overdrive in a car, but issue is boats won't kick down a gear or two.
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Old 09-23-2016 | 07:36 PM
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Not good for the motors or drives ....
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