Differences between OMC & Mercury outboard prop hubs?

[metriccrescentwrench]

Does anyone have a link to a tutorial on the differences between OMC and Mercury prop hubs, what it takes to convert one to the other, etc. Reason I'm asking is I'm looking for a better prop for the '79 Checkmate I just finished rebuilding, and most of the props other Checkmate owners are recommending are for Mercury (I've got a '90 Johnson 200).

 

[steelespike]

Re: Differences between OMC & Mercury outboard prop hubs?

A prop that works on a Merc isn't likely to work on a Johnson.The ratio is slightly different merc rpm is 5600 Johnson is 6,000.The gearcases are likely different shapes.If you get us your prop size,and present max rpm and speed there are guys here that can help. You could also talk to the guys at scream and fly.

 

[Bondo]

Re: Differences between OMC & Mercury outboard prop hubs?

Ayuh,... Generally speakin',...
A Johnny-rude prop will bolt onto a Merc, but a Merc prop won't fit a Johnny-rude...
The depth of the splines are different...

 

[Frank Acampora]

Re: Differences between OMC & Mercury outboard prop hubs?

So: Get your Mercury prop with a rubber hub, press it out and install an OMC hub. Rubber hubs are almost all the same size in prop classes. As long as the outside diameter of the prop hub fits in your gearcase it will work. You need at least a 6 ton press and the cup to a forward gear tapered roller bearing makes a nice tool to insert the rubber hub. I use a lot of black RTV as a lubricant for insertion.