boat came with extra prop but no rubber hub or splines

[Charles_Nelsan]

Hello All,
I'm pretty new to working on boat motors, but I bought a boat that came with 2 Mercury Thunder bolt engines (one was a spare engine), it came with a bunch of extra parts, one being a spare propeller, its brand new but has no splines or rubber hub to connect it to the output shaft of the engine. Not sure if i can press out the old rubber hub of the old propeller and put it onto this new propeller or if i need to buy the rubber and splines separately. i know newer type propellers have plastic hubs that dont press into the propeller. how can i tell if this prop needs a plastic hub or a rubber one. i hope i am using the correct terminology and you guys could point me in the right direction of what to do.
Thanks,
Charles

 

[Frank Acampora]

Re: boat came with extra prop but no rubber hub or splines

First, you can tell if the spare propeller uses a rubber pressed-in hub or the Mercury Flo-Torque (or similar) hub simply by looking. If it uses a pressed in hub, the center of the prop will be a perfect cylinder. If it uses replaceable hubs like Flo-torque, the center will be more squared--slightly octagonal to fit the plastic hub.

Do not try to press in a rubber hub; it will not work. I tried it as an experiment and it failed immediately in use.

Try and find numbers on the prop to see if ot is Mercury or a different brand and buy the correct hub kit for that prop and your engine. They only cost around 40 bucks for the larger props.

If it is a prop that uses a pressed in rubber hub, bring it to a dealer and have it re-hubbed.

While I do press out hubs and re-use them in other props, it is a practice frowned upon. Frequently, the rubber will tear and be destroyed in pressing it out and if it doesn't get destroyed, it may not hold when pressed into another prop.

 

[Frank Acampora]

Re: boat came with extra prop but no rubber hub or splines



This is a Vortex prop designed to use a hub kit. If you look closely, you can see the flats in four spots around the perimeter. I pressed in a rubber hub as seen, and it failed immediately. But hey--it was an experiment and I learned from it.

 

[Charles_Nelsan]

Re: boat came with extra prop but no rubber hub or splines

ok, i will have to take a look at the propeller, i'll go to my mercury dealer and see if they can set me up with the correct hub and press it in. what information will they need? Type of motor and year, number of splines and length of output shaft? thanks for your help

 

[GA_Boater]

Re: boat came with extra prop but no rubber hub or splines

Charles - Before you go spending $$$, check the prop on the motor. The hub you're looking for mat be in use there. The nice thing about the hub type prop is the cost to swap props, as in change pitch for skiing/tubing and another pitch for fishing. A hub of this type can be re-used when you swap props and save some cash. A pressed in hub prop usually cost more. I hope that makes sense.

 

[Charles_Nelsan]

Re: boat came with extra prop but no rubber hub or splines

Ok so the prop is a michigan wheel vortex co2 15. So it's a 10" diameter with a 15" pitch 3 blade. I can a find a hub kit but am wondering if this prop is correct for a 71 mercury 500 thunderbolt. It's 50 hp on a 14ft Starcraft fiberglass boat. Thanks again