Question on prop nut and washer

[dburne]

Hey gang,

In another thread recently, I mentioned I had ordered a new prop wrench ( my first), and upon checking the prop nut on my new Sport 190 discovered it was fairly loose, so I have tightened it.
The prop wrench I ordered, came with a prop nut and couple of the tabbed washers:
http://www.amazon.com/Sierra-Intern...d=1403886466&sr=8-9&keywords=boat+prop+wrench

Now, I had noticed on the prop nut that is on my boat now, the washer only have 4 tabs, and does not have a pocket that the nut goes into like the washer that came with the prop wrench, which also has 6 taps rather than four. So it seems to me the tabs on the current prop washer that is on my boat, do not necessarily lock the prop nut in place like this new one that came with the wrench might.

Here is a pic of the prop nut/washer that is currently installed:

Here is a pic of the new nut and tabbed washer that came with the prop wrench:

So how's come the difference, and should I just go ahead and replace what is on mine with this new one, or just leave it on and see how it does?

Thanks for any tips, new to this prop nut/tabbed washer thing...