How to tell a replacable hub prop

airshot

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Recently bought a 1992 40 hp Mercury 2stroke, 4 cylinder outboard motor. Started looking at spare props, I have been told the came with fixed hub and replacable hub props, how do I tell the difference?? Took the current prop off, poked, pushed, pulled but not finding a hub that comes out. Is this a fixed hub? Looking for an education on identifying these props. After over 50 years of boating never saw a replacable hub, I dont think I have anyway
 

dingbat

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Started looking at spare props, I have been told the came with fixed hub and replacable hub props, how do I tell the difference?? Took the current prop off, poked, pushed, pulled but not finding a hub that comes out. Is this a fixed hub? Looking for an education on identifying these props. After over 50 years of boating never saw a replacable hub, I dont think I have anyway
Pretty easy to tell.....
Replaceable - Flo-Torque X......Merc Version......other makes as well
1662152939968.png
 

airshot

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So that plastic insert will come off in yur hand?? Wanted to know if it might be pressed in.. looks like my prop is a regular non replaceable hub.. oh..by the way....WOW.. have props increased in price !!!!
 

harringtondav

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From what I know each prop manufacturer has their own loose hub design. I don't think there is much interchangeability. Our Mississippi River boating eats props, so I generally use aluminum to spare the prop shaft. I once bought a loose hub prop since the replacement prop is less expensive than an equivalent pressed in hub prop. (Loose hub prop + hub is about the same $$).
I'm back to pressed in hubs only. I don't want to be married to a particular prop brand on account of their hub kit.
 

dingbat

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From what I know each prop manufacturer has their own loose hub design. I don't think there is much interchangeability.
That has not been my experience.
Currently running a Rubex (Solas) hub in a Merc Enertia prop. Had a lot of prop chatter. The Rubex hub was considerably cheaper than the Merc Flo-Torq solution

Here is a cross reference between prop brands

 

harringtondav

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That has not been my experience.
Currently running a Rubex (Solas) hub in a Merc Enertia prop. Had a lot of prop chatter. The Rubex hub was considerably cheaper than the Merc Flo-Torq solution

Here is a cross reference between prop brands

Good to know, and thanks. I favor Solas props. ...in my price range, and seem to perform beyond their price. I purchased two as an upgrade to the VP prop that came on my new SX drive. ...thinking I missed the boat on the Rubex option since I can only put one prop at a time on the drive. ;).
Good local prop rebuilder showed me a Merc hub. ....don't know if it was Flo-Torque. IIRC it was a hard plastic thing with shear tabs that let loose on impact. Not for me. I've limped home many times with a mangled wheel, but better than a free spinning hub.
 

airshot

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Good to know, and thanks. I favor Solas props. ...in my price range, and seem to perform beyond their price. I purchased two as an upgrade to the VP prop that came on my new SX drive. ...thinking I missed the boat on the Rubex option since I can only put one prop at a time on the drive. ;).
Good local prop rebuilder showed me a Merc hub. ....don't know if it was Flo-Torque. IIRC it was a hard plastic thing with shear tabs that let loose on impact. Not for me. I've limped home many times with a mangled wheel, but better than a free spinning hub.
As I am learning about these, I am inclined to think the same way. Only ever sheared one shear pin in over 50 years of boating, haveing plastic drive tabs doesnt sound like a better plan....and they are not cheap in any way !!!
 

Chris1956

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If you look at the back of the prop, and see plastic, the hub is modular. If you see all brass, the hub is fixed.

The prop shells are usually tapered rectangles, with eased corners. Therefore the modular hubs have a lot of surface area to grab.

I have never damaged a prop hub, but I assume it would cause the destruction of the aluminum prop shell.
 

dingbat

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I favor Solas props. ...in my price range, and seem to perform beyond their price. I purchased two as an upgrade to the VP prop that came on my new SX drive. ...thinking I missed the boat on the Rubex option since I can only put one prop at a time on the drive. ;).
The whole idea of the hub is interchangeably of props. You can buy one prop and use it on any number of shafts simply by changing the spline insert.
Good local prop rebuilder showed me a Merc hub. ....don't know if it was Flo-Torque. IIRC it was a hard plastic thing with shear tabs that let loose on impact
Not for me. I've limped home many times with a mangled wheel, but better than a free spinning hub.
As Chris noted, pretty sure you would destroy an aluminum prop before you “sheared” the hub.

I have not run an aluminum prop in years. It’s a whole lot cheaper to replace a $30 plastic insert, if or when the time comes, rather than a stainless prop and or a prop shaft.
 

dingbat

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and they are not cheap in any way !!!
Everything is relative to scale.

Certainly overkill for my 14’ aluminum with the 9.9 on the back.

On the big boat, I spend more than the cost of the hub on food and drinks for the day. Throw in bait, fuel and 2 stroke oil, the hub money equates to change found under the couch cushions. ;)
 

airshot

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I was quoted 240 for a Mercury prop and hub, where a fixed hub was only 140. The cost of just the prop on the replaceable hub was 180, cant see why anyone would go that route?
 

Chris1956

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Prop hubs are usually about $50, and you only need 2 of them. One for a spare. Now you can buy as many different pitch prop shells as you need, that fit that hub. Aluminum prop shells can be had for $75 or so.

You might check some other source.
 

airshot

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Prop hubs are usually about $50, and you only need 2 of them. One for a spare. Now you can buy as many different pitch prop shells as you need, that fit that hub. Aluminum prop shells can be had for $75 or so.

You might check some other source.
I am using a prop shop that is local, tgey have an excellent customer rating, been here for over 40 years. Even looked up Ebay and Amazon, for brand name (not foreign imports) the prop shells are still 140 and up. I have learned that outboard props are more expensive then I/O props. My current motor does not have these plastic inserted hubs so I am going to keep it that way. I can replace the entire fixed hub prop for about the same cost as a shell. Thanks to all that helped explain on this stuff....
 

flashback

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The whole idea of the hub is interchangeably of props. You can buy one prop and use it on any number of shafts simply by changing the spline insert.

As Chris noted, pretty sure you would destroy an aluminum prop before you “sheared” the hub.

I have not run an aluminum prop in years. It’s a whole lot cheaper to replace a $30 plastic insert, if or when the time comes, rather than a stainless prop and or a prop shaft.
I can assure you that the AL prop will self distruct before the plastic does. At least at slow speed..
 

Chris1956

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Gee, do a internet search on the prop brand and model you want. pick the lowest price. Do the same for the hub for that prop.

A local prop shop likely charges a premium to pay for his brick and mortar store, and other skilled labor and tools. Internet sales can be much cheaper. They simply buy from the OEM and sell to you, knowing that most compare prices. They can have real low overhead.

BTW - a lot of sterndrives use the same props as OBs. Mercury V6 motors interchange with alpha 1 drives. Likely others do as well, especially prop shells. I can share prop shells between my Johnnyrude V6 and my Merc V6, although the hubs are different. They would likely fit larger Yammys as well.

If you go with a fixed hub, and it fails, and they do, sometimes without hitting something, you will still need a complete spare prop.

Has anyone seen a modular prop hub fail, w/o hitting anything? I haven't.
 
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