Posts: 3508
Location: Elk River, Minnesota | Well...treats had the first part correct, but the second part is not necessarily so.
The 14 x 17 has more blade surface area and a lower pitch, so it will definitely have a better hole shot, and pulling power. The 13 x 19 is higher pitch with a smaller diameter, which will be for speed on top.
My guess with both of these props the faster one will be the 13 x 19 hands down. The motor will have an easier time turning the 13 diameter prop since it is a full inch smaller than the 14 x 17.
Theoretically speaking here: Lets say your motor tops out at 5500 rpm with the 13 x 19 pitch prop. When you switch to the 14 x 17 two things basically happen..the larger diameter will cause the RPMs to go down (roughly 1/4"=100rpm), but the 17 pitch is 2 inches less which will increase your RPM (roughly 1" pitch=200 RPM). Both props would "theoretically" run at the same RPM by this, but the 14 x 17 will be slower...It will have the "umph" though that you would like for pulling skiers, tubes, boards, etc. The boat will be able to stay on plane a little easier due to the surface area of the props blades.
The 19 pitch will definitely be faster, but it will take a little more to get it "out of the hole" to some extent...but this is offset by diameter some too
I will agree that propping your engine to the Max RPM with a normal load. Then, you will have the power you need when you load up a little more.
All you can do is try the different props. Do a few test runs with each and see which you like better for your style of boating.
Steve
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