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props for triple outboards

Old 02-14-2006, 06:23 PM
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Default props for triple outboards

Need help for new props.

I just bought a 30ft Awesome(Cat) with 3 outboards.
Boat weighs approx. 7-8000 lbs.

3, 2.5, 225efi promax motors.
20inch mids. Counter rotate:

First time with triple outboards
I dont know where to start with props.

What I am thinking:
2 3blades 26-28 on the outside motors
1 4 blade 28-30 on the middle motor.

Please correct me if im wrong:
With three, you run three blades on the outside & 2 pitchs higher, 4 blade in the middle.

Does anybody have an ideas, where to start ?

Anybody have any idea of engine height:
I think the center is higher then the outsides?

Any help would be great.
Thanks
Jeff
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Old 02-15-2006, 09:09 AM
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Smile Re: props for triple outboards

Do you have any props to try?

Not everybody running these boats runs 3 and 4 blade combos. Running different pitches is quite common. However, you may run the center higher on this application. Also, different diameters with the outer and inner props is common. Typically these set ups can run the engines at a very elevated height (until you run out of H2O pressure). Your pitch guesses are more than likely right on. The ProMax engines will rev limit at about 6800 rpm. Prop them right to 6750 rpm.
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Old 02-15-2006, 11:37 AM
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Default Re: props for triple outboards

Welcome to the world of triple engine boats. The option regarding set up and props are almost limitless.

You have a number of options regarding props. Depending on how you plan to use the boat you may consider a different prop that an outboard cleaver. There are other props on the market that can outperform the cleavers in most areas, sometimes even top end. As far as using a 4 blade prop on the center and three blades on the outer that is not necessarily a rule of thumb.
The best place to start is with some kind of baseline. If you can try a set of props and get some performance numbers that would be helpful. Take note of how the boat handles and what was good and bad about the props you tested will help to determine what would be the next step.

If you have any more questions don't hesitate to call. Triple engine boats can be a handful with set up and props.

Matt
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Old 02-15-2006, 12:34 PM
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Default Re: props for triple outboards

Well, thanks Gentlemen

Now Im even more confused then before?

CLEAVERS: Who makes a better prop for this cat ?
I have a few 26 & 28 14.5, which I had on an STV. But they are not cleavers & do not provide bow lift.
They are mostly drag props.

DIAMETER: Should I go bigger then a 14.5 ?
Should I go bigger on the inside or outside?

Would all four blades run better since this boat is so heavy or should I start with three blades ?

Do you have to pitch 2 higher for the center motor or can it run the same pitch ?

I have never run this boat. Bought it and installing 3 motors.
At one point it had 3 28 cleavers on it with old 2.4s, but it never did run good.

I know the boat has bottom pick up including the lower unit.
I guess this is so you can run the motors higher.

I dont think the center motor has bottom pick-up, but the two outside motors pick up from both.

I know I have to play with it, but any idea what props to start with?

I left a message with Tim at Performance props to see what he thinking. He is out unitil Monday. I will posted what he tells me.

I have no idea what she will turn, I was just told its very heavy & had no bow lift.
Its need more air under it.

It also does not have trim tabs. Would it help to plan & run a bigger prop if it had trim tabs ?

I know I have to start somewhere to see what she does.
I just need to know what size props to start with.

Since I have to buy three props., I dont want to do that more then twice or three times.

Thanks for the info., all the help is great & I will keep all posted as soon as testing starts.

Just need to know where to start?

Thanks
Jeff

P.S.: I live on the lake & have three kids. I want to run the boat with the family & then run the local poker runs on the week-end.
Mid 80s would be nice to start?
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Old 02-15-2006, 06:45 PM
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Smile Re: props for triple outboards

Can you supply me with the weight of the boat, by actually weighing it? I only need the hull to start with.

I have some ideas. We need to determine some pitch ranges. I got your email and can communicate that route.
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Old 02-15-2006, 07:59 PM
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Default Re: props for triple outboards

100% agree

Ok, the problem.
I live in Montreal Canada. Frozen Solid

The boat is in Alabama getting the motors put on.

I can get it done in the next few weeks.
I can get them to weigh the boat & trailer at local weight station, then get them to drop the boat & reweigh the trailer.

I can also try with AwesomeCat, but I dont know if they would have the information.

Let me see what I can do.
bbladesprops, I will give you a call tomorrow from the office.

Was told today that she had no problem going on plan with 28 cleavers (3-2.4efis), but it would only run about 70s.?
I dont think they were good motors, nor were they good props.

I need three to start & hope you can rework them?

Keep you posted,
Jeff
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Old 02-26-2006, 08:29 AM
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Default Re: props for triple outboards

have you tried calling Mazco? He specializes in fast outboard props. A friend of mine used Mazco props for a tripple application and he hit it on the nose first try. Hard to find another set of props as fast. Hydromotives seem to work real close though ( and are stock out of the box). The big drawback is the Mazco props are labbed really thin. They don't last forever.
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Old 02-27-2006, 10:12 AM
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Default Re: props for triple outboards

Mazco props ?

Thats a thought ?
I run a 30 on my stv & love it.

The boat will hit the water for testing in about 2 weeks.
I will post what she does.

Out of my collection of props.
I have two 26 & a 28 for the center.
They are choppers.

I have to start somewhere.
Keep you guys posted with this set up.

Thanks, keep them coming

Jeff
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Old 04-17-2021, 08:29 AM
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Question on triple props, I have an intrepid 407 with Mercury 400r’s currently using Mercury Revolution lab finished 14.6 with 20 pitch, center motor had one blade fail from fatigue, problem with pandemic getting these from Mercury, the only thing I can find in stock are either 19 pitch or 21. As a temporary fix until lab finish comes in, thoughts on using either one of these keeping the other 2 motors with their original props.
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Old 04-18-2021, 01:08 PM
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Originally Posted by [email protected] View Post
Question on triple props, I have an intrepid 407 with Mercury 400rs currently using Mercury Revolution lab finished 14.6 with 20 pitch, center motor had one blade fail from fatigue, problem with pandemic getting these from Mercury, the only thing I can find in stock are either 19 pitch or 21. As a temporary fix until lab finish comes in, thoughts on using either one of these keeping the other 2 motors with their original props.

We can Lab either to work fine with the 20's.
We'll need numbers from the performance to know how far to adjust either prop.

Let me know if we can help.

Brett
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