Prop replacemnet test

[fish_on]

I have a 21' seahawk with a 200 Yamaha. I have the stock 19P black stainless prop. I wanted a new prop so I went to Tacoma Prop. I took my original prop in and had a good long talk with them. They measured my original prop, it actually measured as a 17P with the cup making up for the additional 2" to make it a 19P. I purchased from them a Vortex polished stainless 19P that measured 19 and had cup to boot making it around a 20 or 21 total pitch. The new prop was also vented. Here are my results.

The original prop ran the motor at 6+K and topped out at 46mph with 70gal of fuel, 3 people and full load of gear and coolers.

The new prop runs 5.5K top speed of 46mph with 70gal of fuel, 3 people and full load of gear and coolers. I can hit 6K by trimming up but there isn't any speed advantage. The new prop is quieter, I have better reverse, the boat is easier to steer, the hole shot seems the same, the bow ride is a little softer through chop and I think that is because of a different bow angle. I still have the prop torque problem.

I am going to go back and swap the prop for a 17P Vortex and see what does. I'll post the results when I'm done.

[D-tangle]

Thanks for the info. I am interested in what you find. Will the new prop have a cup to the back of the blades? This, I believe, adds torque to the spin of the prop. Let us know.

[fish_on]

I had one bad piece of info it's an Apollo prop not a Vortex.

I switched to a 17 pitch with cup to make it the same as the stock Yamaha. My first prop was out of balance so I couldn't get a good test. Tacoma prop replaced the prop but I had them spin it first and it was even worse, so they balanced the first one and it's perfect.

The 17P Apollo gets my RPM back to 6K, and my speed back to 46ish. Conclusion the difference in rake and geometry didn't make any real performance gains. BUT the new prop lifts the boat out of the water a bit more and gives me a different bow angle on plane. This different angle makes the boat ride better through chop and handle better in turns. The smoother ride means more speed in rougher water or a nicer ride at slower speeds. :wink: The OE Yamaha prop has now been stowed in the bow as a spare prop and we'll see how the Apollo holds up.

As a side note if you buy a Michigan Wheel prop (Apollo, Vortex, etc.) buy it from a prop shop so if you have balance issues you can exchange it. Tacoma Prop informed me the at it's not unusual for these props to be out of balance and need some work.

[Starfish]

Sounds like you're getting pretty good performance out of your current setup. The stock Yamaha stainless props are actually darn good props from what I've heard (and from my experience on a smaller motor, a Pro-V 115 a few years ago). Sounds like your new Apollo is doing OK too.

By the way, a prop with a lot of cup lets you raise the motor higher in the water column before it blows out. You can raise the whole motor a hole or two higher on the transom and raise your RPMs and lower drag and sometimes pick up a few miles per hour. You may need to go to a higher pitch prop to compensate for the higher RPMs.

It might be worth trying a spin with a few Merc props such as a Tempest Plus. They gave me the best performance on my rig (21' Tundra with 225hp Merc). Also if you want every ounce of performance you can try sending a prop to a guy in Wisconsin named John Janaky at DAH Custom Propellers- the guy is quite the artist at tweaking your prop to fix any performance issues.

But all in all it sounds like you're pretty satisfied with the rig as is-- any more gains you would get might not be very cost-effective unless you damage a prop and need to get a new one anyway.