Prop advise

Lt 55

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May 8, 2008
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I just bought an 07' Chaparral 204 with a Volvo Penta 4.3 GXI 225 hp.We took the boat out last weekend and ran 48mph at 4800 rpms WOT.I had my family of 4 with 3/4 tank of gas and smooth water.Volvo's upper range rpms for that motor is 4800.The prop I have now is a 14x21 4 blade alum prop.I want more holeshot for wakeboarding and skiing.Should I go to a 20 pitch or maybe even a 19? Or stay with what I got? I don't care about top end speed.Thanks for any advise.
 

Lt 55

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May 8, 2008
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Re: Prop advise

Also i forgot to ask.Would I need a hub kit? Or does that depend on what prop I get? Shouldnt I already have one on there?Thanks again.
 

bowman316

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Oct 21, 2008
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Re: Prop advise

Every brand new prop needs a hub inside of it. They come empty in the center. It is easier to buy a used prop on e-bay with the hub already in it. And no, you can not get to old hub out of ur old prop, it won't come out. each degree you drop in pitch will add 200 rps to your top end, you don't want to add so much, that your motor is over revving. how long is your boat anyway? I think you are too big to be pulling skiers. You should already have good pick up with that prop on it.
 

Dhadley

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Feb 4, 2001
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16,978
Re: Prop advise

Props with pressed in rubber hubs come with the hub already in it. Props that use field replaceable hub kits, like the Flo Torq or similar, don't come with a hub kit. Those are refered to as "square bore" props. Yes, the pressed in rubber haubs can be changed but have to be changed at a prop shop. Pitch is measured in inches, not degrees. Rake is measured in degrees.
 

Lt 55

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May 8, 2008
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Re: Prop advise

The prop that I have now does not have vent holes in it.It is beatup on the edges.The boat is 20 ft.I understand about the hub.When we ran the boat with about 8 people( 4 kids 4 adults ) and a full tank of gas, I was wanting more pickup.I would usually run the boat with my family of 4 and maybe 1 other person.
So if I go to a 20 pitch prop and don't run past 4800 rpms I should be ok?And still get a little better holeshot?
 

Lt 55

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May 8, 2008
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Re: Prop advise

Has anyone used smart tabs for a better holeshot?Or I guess it would be to get on plane quicker.
 

bowman316

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Oct 21, 2008
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Re: Prop advise

If I was you, I would have 2 props, one for heavy loads. sking, and one for light gass efficent loads. And that way u have a back up prop on board if u bend ur prop.
And by smart tab, do you mean a fin that goes on the cativation plate? I think those just slow you down, because they are below the water line.
 

Dhadley

Supreme Mariner
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Feb 4, 2001
Messages
16,978
Re: Prop advise

Used correctly the Smart Tabs , or Bennets or Lencos or etc, should help holeshot.
 

180shabah

Rear Admiral
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Mar 26, 2005
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4,995
Re: Prop advise

Smart tabs are one of the best "bang for the buck" purchases you can make for a sterndrive. They are trim tabs that use gas struts instead of hydraulic(or electric) rams. They are "automatic" but not adjustable on the fly.

They DO NOT moutn to the anti-ventilation(cavitation is a different issue) plate. That is a hydrofoil, and has no place on a performance boat.
 

bowman316

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Oct 21, 2008
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Re: Prop advise

do you think Hydrofoils work on outboards? I had one on my 70 hp evinrude, and it would drag below the water line at wot. So i think i hurt more than it helped. Maybe if I raised my motor up a bit, so it was right at the water line.
 

MikDee

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Jun 6, 2007
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4,745
Re: Prop advise

I just bought an 07' Chaparral 204 with a Volvo Penta 4.3 GXI 225 hp.We took the boat out last weekend and ran 48mph at 4800 rpms WOT.I had my family of 4 with 3/4 tank of gas and smooth water.Volvo's upper range rpms for that motor is 4800.The prop I have now is a 14x21 4 blade alum prop.I want more holeshot for wakeboarding and skiing.Should I go to a 20 pitch or maybe even a 19? Or stay with what I got? I don't care about top end speed.Thanks for any advise.

IMO, you can't do better then the prop you have, less pitch would cause you to overrev! Maybe a "vented" Hustler prop in 21' pitch would give you a better holeshot, and even more top end, but drop your rpms some? The other feasible option is "automatic" Smart tabs, they will help with holeshot, getting on plane faster, and low speed wander, regardless of what prop you have. You're at a pretty good rpm range with the prop you've got, I'd try the tabs first. Of course if you wanted to be daring, try a high five prop, but they are pricey! You'd probably have to drop down to a 19" pitch because it's Stainless, and has one more blade.
 

Tail_Gunner

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Jan 13, 2006
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6,237
Re: Prop advise

You want a 18p baypro 11 4 blade ss made by stilleto. The lower pitch will jump you out of the hole stronger than the 21p alum the prop will carry you onto plane at lower speed's and you can still dig the leg in to create a large wake for boarding and trim her way out to reduce the wake when sking...They are excellent I/O props and you may not lose any speed...Plz note that with tab's you will lose your wake..been there done that...and i really like nauti's trim tabs...absolute good stuff....

Ohh and you will have aboat the pulls like a tractor at any speed and run noticalby smoother..
 

Lt 55

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Joined
May 8, 2008
Messages
7
Re: Prop advise

Thanks for the ideas and opinions.I don't want to mess up the wake with smart tabs.Maybe manual-control type tabs are the way to go.I'm not sure about the prop sizing.I'll report back when I figure it out.If anyone else has some input, please feel free.Thanks again.
 
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