Pontoon Boat & Deck Boat Forum

I found a place called turning point propellers and they seem to have a nice calculator. I was wondering if anyone else has used this and if so how did it turn out ??

k5guy38 wrote:I found a place called turning point propellers and they seem to have a nice calculator. I was wondering if anyone else has used this and if so how did it turn out ??

I just tried it. It was off by 2 pitches for me. It was telling me a 17P for speed and a 15P for water sports. I need a 19P, 15P on my boat is just nuts.

I just tried it too. I currently have a Yamaha Reliance SS 14.5 dia with a 15 pitch on the engine. I'm only getting a max WOT of 5700 RPM.

The prop calculator suggested a 14.25 dia X 15 pitch for water sports, and a 14.25 X 17 P for speed.

So, pretty close in my case.

Strake wrote:I just tried it too. I currently have a Yamaha Reliance SS 14.5 dia with a 15 pitch on the engine. I'm only getting a max WOT of 5700 RPM.

The prop calculator suggested a 14.25 dia X 15 pitch for water sports, and a 14.25 X 17 P for speed.

So, pretty close in my case.

Not sure what your RPM's at WOT are supposed to be, but you will lose RPM's with a 17P prop if you are running a 15P now.

Scott1 wrote:

Strake wrote:I just tried it too. I currently have a Yamaha Reliance SS 14.5 dia with a 15 pitch on the engine. I'm only getting a max WOT of 5700 RPM.

The prop calculator suggested a 14.25 dia X 15 pitch for water sports, and a 14.25 X 17 P for speed.

So, pretty close in my case.

Not sure what your RPM's at WOT are supposed to be, but you will lose RPM's with a 17P prop if you are running a 15P now.

You're correct...... I should be getting 5000 to 6000 WOT. The head mechanic who did my PDI on the boat and engine got 5800 rpm WOT when they set it up with an alum 14.5 X 15 P prop. All I did was switch it out for a SS prop. I wasn't suggesting that I should use a 17P ..... just stating what the online prop calculator came up with. What would the drop in diameter do from a 14.5" down to a 14.25" ??? I get the pitch part of the story, not sure how the diameter affects either power, or top end.

If you're relatively close to the 6000 rpm redline on a Yamaha, it's close enough.
To get exactly to the 6000 rpm's will be very costly in the world of $500 stainless steel props.
As long as you're not experiencing prop blowout or ventilation and it you can handle the maximum load you normally see, 200 rpm's is very little difference.

Ya i am wondering about the diameter also i have a 16x14 now and the prop calculator says 14.5x17 also.

k5guy38 wrote:Ya i am wondering about the diameter also i have a 16x14 now and the prop calculator says 14.5x17 also.

Bigger Diameter is better on a pontoon 99% of the time. They (the prop company with the calculator) may not make a larger diameter prop than 14.5" for your engine so that's what the calculator recommends.

They recommend the 14 for speed and a 15x15 for water sports. The problem I have is in a normal to me situation I can over rev my rpms by around 400. The tach is new and was verified by the dealer who put it in. The pontoon has gobs of power but lacks in the speed range. I am afraid that by going to a 14 verus a 16 in diameter I wil still be over revving my motor.