Pontoon Boat & Deck Boat Forum

I took my prop off last night to check out the hub setup. I didnt realize how its basically just a piece of plastic. Has anyone ever had one break? Is this something I should buy to have a spare on the boat? I have a new 115 hp Four Stroke Merc.

If you hit something hard it could break. I would always carry a spare prop just like a spare trailer tire.

I just looked at the extra hub that came new with my Optimax 75. It is indeed a composite material. There are generally 3 reasons to make something like this hub out of composite material.

1. It doesn't need to be any stronger than the plastic offers.
2. It is intended to be the "weak link". It is a sacrificial part, one that is cheaper to replace than the more expensive parts around it.
3. The manufacturer is just making it cheaper to try and save cost.

I'm no engineer, and I don't know enough about boats yet to know what combination of those 3 they did it for. But I do know a spare hub came with my motor right from the factory. So it would definitely be in your interest to get a spare. And the other experienced guys on this forum also recommend a spare prop, nut, and cotter pin.

So for those of us that don't know anything...

Can someone post a link to what exactly we should have as spares?

I can figure out things as I go but know nothing about props...hubs..etc if these things are all standardized I would love to know exactly what I need (and should have spares of) before I run into trouble? Thanks again for putting up with my ignorance....

Lurch77 wrote:I just looked at the extra hub that came new with my Optimax 75. It is indeed a composite material. There are generally 3 reasons to make something like this hub out of composite material.

1. It doesn't need to be any stronger than the plastic offers.
2. It is intended to be the "weak link". It is a sacrificial part, one that is cheaper to replace than the more expensive parts around it.
3. The manufacturer is just making it cheaper to try and save cost.

I'm no engineer, and I don't know enough about boats yet to know what combination of those 3 they did it for. But I do know a spare hub came with my motor right from the factory. So it would definitely be in your interest to get a spare. And the other experienced guys on this forum also recommend a spare prop, nut, and cotter pin.

It is definitely number 2. It is as strong as it needs to be under normal operating conditions and will sacrifice itself to save lower units.

Mosnowman wrote:Can someone post a link to what exactly we should have as spares?

I can figure out things as I go but know nothing about props...hubs..etc if these things are all standardized I would love to know exactly what I need (and should have spares of) before I run into trouble? Thanks again for putting up with my ignorance....

Well, I don't know about all that, but I carry an exact twin to the prop on my motor, along with a spare prop nut, and the tabbed washer that keeps it from spinning off, and a thrust washer. In other words, everything that comes off when you replace the prop, I have a spare. I also carry a tube of prop grease, and of course, a floating prop wrench. And a piece of 2 X 4, about 8" long - that's needed to change the prop. Oh, and a pair of needle-nose pliars to bend the tabs on the washer.

I carry ALL of this in a padded, "soft-sided" cooler bag, that keeps this stuff from banging around, and damaging the tin on my pontoon.

Mosnowman wrote:So for those of us that don't know anything...

Can someone post a link to what exactly we should have as spares?

I can figure out things as I go but know nothing about props...hubs..etc if these things are all standardized I would love to know exactly what I need (and should have spares of) before I run into trouble? Thanks again for putting up with my ignorance....

This is the Flo Torque hub.



The plastic/composite piece is designed to shatter when the prop strikes something solid. This minimizes damage to the prop and prevents damage to the lower unit gears.

Although the photo above shows all the parts, which runs around $50-$60, all that's really needed is the plastic hub. The other parts are brass (except for the locking washer) and seldom fail. The hub runs around $25 or so.

Personally I'd want to have spares on board of all the parts concerning the prop + a spare complete unit. One more than one occasion I've had to swim and change out a damaged prop on the water myself. Though I been lucky and have managed not to drop any components into the drink I also realize how easily it could happen, so spares are on-board. In reality it's rather cheap insurance for what otherwise could be a ruined weekend.