I bought a used SS prop off of craigslist as it was the size and pitch I want to try for only $100. Come home to test fit and find out that a 15 spline hub is not a 15 spline hub. I have read online now that the spline depth is different for a merc compared to an OMC. Can I press the hub out of my new to me prop? Thanks for any help as I am still learning about props. In the pics the new prop does not have a rubber hub.

That's why I sold you that 18 inch OMC prop. I knew you were the only guy on the planet that could use it. It might be possible to go to a machine shop and get one end or the other machine a little bit shorter so that the Hub would fit, but I think the best bet is to get back up on eBay and get a hundred bucks for it.

That's why I sold you that 18 inch OMC prop. I knew you were the only guy on the planet that could use it! It might be possible to go to a machine shop and get one end or the other machined a little bit shorter so that the Hub would fit, but I think the best bet is to get back up on eBay and get a hundred bucks for it. It also might be possible to press the entire Hub out and press in a new Hub that is OMC instead of Mercruiser, but I think you're getting into too much money for a used prop.

You also could have come on here and ask ahead of time if a Mercruiser prop was going to fit your king cobra. And you would have gotten a resounding no from everybody on Oso in 5 minutes. But if the crop cost you a hundred bucks and it's in good shape, you're not out any money. Somebody's going to be happy to take it off your hands. Swap Shop.

Thanks for the info, yeah I should ask but I always like learning the hard way LOL. I probably am the only one on this site with a King Cobra left on an offshore style boat.

We can weld in a SS sleeve and then use the correct adapter sleeve. We have this stuff in house.
This is about a $150 option.

Let me know if your interested.

Brett

Brett thank you for the reply. I was actually able to get that hub pressed out and used an existing Flo-Torque hub off my 4 blade Hydromotive prop I can't use at Tahoe. I would like your advice on a new prop though. I was able to take one last trip to Tahoe last weekend and have the motor pretty dialed in now.
I was able to get my 14.5x20 Raker 3 blade stainless to 57 mph and topped out at 5100 rpm (My peak HP and Torque is at 5400 rpm).
The 14.5x18 Raker stainless pulled too much rpm and only went 48-50 ish.
I was also able to try that new prop and I think it has had some work done to it as I could not accelerate with this prop and it just blew out. I had to feather it to get up to rpm and it only pulled around 4700 rpm and around 53 mph. I was thinking I need a 19 pitch prop but would like your advice on what I need and what design would fit best for my boat. I am after a top speed prop as I have others to play with.

Ah yes, that prop was one of those square bore castings before the Flo-Torq hubs came out. They actually were part of the starting point for the current hub configuration.
You can contact us and we can send you a 19 Mirage+ and a 19 Tempest + through our test program. For top speed a 3 blade Lab Finished will have the best top end.
I assume the boat is in your avatar?

Brett

Yes it is a 30 ft Advantage

That prop will need the proper thrust washer (not OEM OMC) and the first inch or so bored out to accommodate the wider propshaft at the thrust washer end. The OMC shaft tapers out larger. My Mazco's are done this way.