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Richard Wing

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I am new to boating I currently have a 2016 Bennington ssrx with a 90 Yamaha.
The Max RPM I get is between 4200 and 4300.
From what I researched I'm supposed to be between 5500 and 5800 RPMs. The prop I have on the motor is a 13.25 X 17. I have called two different dealers and found the ballpark but 13 and 5/8 X 14 or a 14 X 14. My question to y'all would I increase speed or would this make my boat go slower going down in prop size.
FYI max speed for my boat is 20 miles an hour.
 
Richard Wing said:
I am new to boating I currently have a 2016 Bennington ssrx with a 90 Yamaha.
The Max RPM I get is between 4200 and 4300.
From what I researched I'm supposed to be between 5500 and 5800 RPMs. The prop I have on the motor is a 13.25 X 17. I have called two different dealers and found the ballpark but 13 and 5/8 X 14 or a 14 X 14. My question to y'all would I increase speed or would this make my boat go slower going down in prop size.
FYI max speed for my boat is 20 miles an hour.
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Looks like you are way over proped with a 17p on the 90 Yamaha. I don’t even have that size on my motor (200hp) Your motor is working too hard to turn it, and that’s why you are so low on RPM’s. That is not good on your motor at all, so you need to go down in prop/pitch to do right by that motor. Frankly, I think you will pick up a little bit of speed because your motor would be spinning the new right sized prop better.

I think you will still be too large with a 14p, but I am not familiar with those sized motors either. My guess would be more of an 11-13p. Hopefully some others with a 90HP can chime in with their prop size for comparison purposes.
 
That would be beneficial for me if somebody else can chime in on their 90 horsepower just so I can do a general comparison
 
What size is your boat? I have a 2575 with a Yamaha F100 and run a 4 blade 13 pitch solas. My boat is big and heavy but I can hit 23mph on GPS with me, my 11 year old son and a full tank of gas.
 
Richard Wing said:
I am new to boating I currently have a 2016 Bennington ssrx with a 90 Yamaha.
The Max RPM I get is between 4200 and 4300.
From what I researched I'm supposed to be between 5500 and 5800 RPMs. The prop I have on the motor is a 13.25 X 17. I have called two different dealers and found the ballpark but 13 and 5/8 X 14 or a 14 X 14. My question to y'all would I increase speed or would this make my boat go slower going down in prop size.
FYI max speed for my boat is 20 miles an hour.[/QUOTE

I have a 90 command thrust on a 2017 20 SLMXP / lifting strakes / 2 25" toons - can touch 30 mph / 5100 RPM myself in perfect conditions - cruise 3500 at 14 MPH with 3 people
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Richard Wing said:
I am new to boating I currently have a 2016 Bennington ssrx with a 90 Yamaha.
The Max RPM I get is between 4200 and 4300.
From what I researched I'm supposed to be between 5500 and 5800 RPMs. The prop I have on the motor is a 13.25 X 17. I have called two different dealers and found the ballpark but 13 and 5/8 X 14 or a 14 X 14. My question to y'all would I increase speed or would this make my boat go slower going down in prop size.
FYI max speed for my boat is 20 miles an hour.
Click to expand...

13P / 4 prop
 
you need a 11 or 13 pitch prop at best my Yamaha 115hp uses a 13 Pitch at 6000 rpms. you are way over propped. when u get the rpms up you will be amazed how much better your boat does.
 
I have a 14 inch prop coming Wednesday as soon as I get it I'll put it on take it for a drive and I'll let y'all know what happens. that's far thank you very much to everybody that has made a comment
 
Richard Wing said:
I have a 14 inch prop coming Wednesday as soon as I get it I'll put it on take it for a drive and I'll let y'all know what happens. that's far thank you very much to everybody that has made a comment
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regardless of what prop you wind up with you must be able to turn close to 5800 to 6000 rpms, my bet is you will wind up with a 13 5/8 dia. prop with a 11 or 12 pitch to get the desired rpms and good performance out of your boat, of course all testing has to be done with clean pontoons also.
 
I tried 5 different ones on mine before I settled. When I bought the boat, it had a 17 pitch and I could only turn 5000 rpms.
 
That’s fantastic! Congratulations!
 
Richard Wing said:
I have installed the new prop 13 5/8 X 14. My 20ft ssrx now goes 6100rpms at 26.3 mph. The old prop was a 13.25 X 17 and the max RPMs was 4300 at 20 mph. thank you all for the information has been very helpful hopefully one day I can reciprocate
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Awesome news! Congratulations. I am glad your work and inquiries have payed off, and you are seeing positive results. Hope you enjoy some great times on that “newly performing” boat.
 
Eric Eichner said:
I have a White Yamaha 300 what prop would you run?
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Well the white Yamaha actually pulls a little harder than the grey, so...

Just pulling your leg. Depends on your boat - 3 log presumably, SPS or ESP, 23-25 ft, weight etc. But generally speaking in that HP range you're looking at a 17-18 pitch prop. Yamaha makes a Salt Water Series II that is a popular prop, while Mercury/Quicksilver make an Enertia prop that is also very good. Solas props are less expensive than the other two but many owners find them more than adequate.

Prop design, diameter and pitch all create different performance tradeoffs so you may have to do some testing under varied conditions to see if you are satisfied with the results. For example, with a particular prop you may get good hole shot and top speed just by yourself and half tank of fuel, but when you load it up with 6 people, full tank and are pulling tubes it could be a dog. Many folks prop their boats based on the most frequent scenario they will likely encounter, while others prop to the heaviest load they may expect. I think what you choose comes down to preference.

Under all scenarios you don't want to have your engine out of the manufacturer's operating range, which for Yamaha is typically 5000-6000 RPM at WOT. Fall below that range and you'll lug the engine and potentially cause issues, while above that range and you'll be leaving performance and fuel economy on the table.

There is a prop section in the forum that you can dig around in, or do a search query for your model boat and engine and some suggestions should come up.

Good luck!
 
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