SS prop for?

[Deepdiversplit]

Here's the problem. I bought a SS prop 14.5x20 3-blade 15 spline for my alpha drive that the seller said it would fit because in came off of a mercruiser. It doesn't fit, the hub is to long and I am unable to fit the locknut properly. I would like do find out what it does fit so that I may be able to sale it to someone that can use and benefit from it and I could use the cash. Someone suggested that it might be for 150hp > Yamaha?
There are some numbers stamped on the hub where the size and pitch are stamped. The numbers are 21402 and 26681 and on the side of the prop it is stamped D997B and that is all of the info on the prop. Fits 1" diameter shaft and the hub is 4 5/8 inches long.
Any help would be greatly appreciated!

 

[fatlenny]

A photo might help to see what you are working with (prop shaft, thrust washer without the prop attached, the prop nut after install, and the spacing between the prop and the gear case after install.) there are different styles of thrust washers that go on the prop shaft prior to installing the prop. At least this is what I have found on my merc outboards. I have to swap this out depending what prop I am swapping to. if you are using your old one and it does not have a recess like this one, this may be your issue. This recess sets the prop down a little further putting it where it needs to be in my applications. I hope this helps.

 

[Chris1956]

Take a look at the spline length of the prop. Mercruiser and Mercury OB props have full length splines. Johnnyrude props have splines that are about 1/2 as long as the prop hub, starting from the prop nut, forward. Not sure what Yammie has.

Luckily, larger OBs and MerCruisers share prop hub sizes. These hub sizes are 3-3/4". Smaller OB's use 3-3/8 hub sizes, or smaller.

If the prop has a removeable hub, you may be able to get the correct hub for your MerCruiser.

Alternatively, I was able to convert a Mercury OB prop to run on my Johnnyrude, by drilling out 1/2 of the splines. Drilling out the splines allowed the prop to go onto the propshaft more. I needed to grind a Mercruiser thrust hub a bit to make that work as well. Just some ideas for you to consider.

The hubs on MerCruiser and Johnnyrude props are about the same overall length, but the position of the prop on the propshaft is controlled by the length of the splines and thrust washer.

 

[Deepdiversplit]

Thanks for the ideas y'all. I'll take your info and run with it and see what I can do.

 

[QBhoy]

Hi. Not impossible, but quite unusual for most of the normal merc stainless props for that gearcase to come in even pitch sizes. Outwith more expensive merc props like enertia and similar.
That aside, the number (without looking it up) given there doesn’t look like a mercury part number perhaps.
Usually you’ll need a specific hub kit suitable for each type or brand, for most props these days. These come with specific sized thrust washers too. Alpha ones and bigger merc outboards from 150hp and above (or CT) have a 4 3/4 gear case and usually off the shelf props from mercury will mostly be odd pitch increments (but not exclusively). Smaller gearcase outboards from around 75-125 (roughly and CT being the exception) are 4 1/4” from memory…and will generally be found on even sizes (but not exclusively).