Looking for a better prop for 21' Pontoon with Yamaha F115

[jfixit1]

I have a 2018 21SL pontoon (25" tubes and no lifting strakes) with a Yamaha F115 HP outboard (max for this toon). The outboard came standard with a 13.5 x 15 AL prop. I purchased this boat new and I have over 123 hours on it. I am looking to upgrade both midrange performance (when tubing and cruising with heavy loads) and improved fuel economy. I used to have a fishing boat and loved the 4 blade SS prop I had on it but unsure of real world performance on a pontoon. The Yamaha prop selector is of little use and it seems there are as many opinions as ... but looking for real experiences of either a 3 or 4 blade SS prop on a pontoon with similar size and with a Yamaha F90 or F115 as both use the same block.

Specs for the engine: Full throttle range 5300-6300 RPM
Specs of this boat with a light load: WOT 6200 RMPs (suggests a higher pitch but would reduce low end performance), holds plane at 3500-3600 RPMs and tops out at 31 MPH.

The boat is used for everything from large group cruising, pulling tubes and fishing. I am will to give up a little on the top end but not more than 2 MPH as I am on a large lake.

Has anyone upgraded to a 3 or 4 blade stainless steel prop with a similar boat/motor configuration and if so which one?

Thanks

 

[PartyBarge]

Sounds like your performance is not at all bad now. Sorting through the Yamaha Performance Bulletins looking at combos close to yours should give you a pretty good idea what works. Focus on pontoon rated props. Link below:

Performance Bulletins - Yamaha Outboards

Yamaha Outboard Performance Bulletins provide in-depth performance information on hundreds of boat and engine combinations. Browse Performance Bulletins here.

yamahaoutboards.com

Our pontoons are different, but you too might like the Quicksilver Nemesis 13p pontoon prop. Your motor likely has a different gear ratio making the same prop I use work for you. I also like the Yamaha Talon 12p, but I expect that one may run too much RPM on your motor.

 

[Vikingstaff]

Not to be a party pooper here. I just don’t see any point in a SS prop on a pontoon boat with a motor under 150HP. With a 115HP, you really are better off turning an aluminum prop. Not enough HP to flex it, and you have a lighter prop to spin, repairable, and no risk to lower unit if you hit a hard object.

Also, I don’t think a 4 blade prop helps you better achieve your goals over a 3 blade with a dual toon, no lifting strakes and the 115. You can do a little bit with that set up, but only so much due to the boats propensity to blow through water vs. get up on plane.

Looking at your numbers, I am not sure you’ll get better performance from much else.

 

[PartyBarge]

Not to be a party pooper here. I just don’t see any point in a SS prop on a pontoon boat with a motor under 150HP. With a 115HP, you really are better off turning an aluminum prop. Not enough HP to flex it, and you have a lighter prop to spin, repairable, and no risk to lower unit if you hit a hard object.

Also, I don’t think a 4 blade prop helps you better achieve your goals over a 3 blade with a dual toon, no lifting strakes and the 115. You can do a little bit with that set up, but only so much due to the boats propensity to blow through water vs. get up on plane.

Looking at your numbers, I am not sure you’ll get better performance from much else.

Agree with most of that, but until you've run a Spitfire/Nemesis on a pontoon with a 90-115 class motor you can't know what you're missing. Your argument against a 4-blade is exactly what makes them a player.

Yes, it's a different application, but I go a step beyond 4-blade to a 5-blade (Merc Hi5) for water sports on our tow boat. Yes, it costs about 4-5 MPH ( rev limiter) off a very light weight top end against the best 3-blade, but I don't need that 56 MPH anyway. That said the 4 3/4" case version of the Nemesis is a very good all-around prop there too.

 

[Rssuttle]

Agree with most of that, but until you've run a Spitfire/Nemesis on a pontoon with a 90-115 class motor you can't know what you're missing. Your argument against a 4-blade is exactly what makes them a player.

Yes, it's a different application, but I go a step beyond 4-blade to a 5-blade (Merc Hi5) for water sports on our tow boat. Yes, it costs about 4-5 MPH ( rev limiter) off a very light weight top end against the best 3-blade, but I don't need that 56 MPH anyway. That said the 4 3/4" case version of the Nemesis is a very good all-around prop there too.

Have you changed your prop and are you getting better numbers?

 

[PinnacleG23]

I've tested a number of props on two different bennington boats. Three blades, and four blades. What I can tell you is first Stainless will outperform aluminum significantly. Second the Mercury Enerita is by far the superior pontoon prop on the market. I would recommend a 14P Enerita I'd go down one pitch because the Enerita has a lot of cup and bite. Even at the lower pitch, your likely to see higher speeds due to lower prop slip with the enerita.
Its an amazing prop. Outperforms the revolution 4, Powertech OFS4, Mirage plus and Yamaha SS series.

 

[Rssuttle]

I have a 2018 21SL pontoon (25" tubes and no lifting strakes) with a Yamaha F115 HP outboard (max for this toon). The outboard came standard with a 13.5 x 15 AL prop. I purchased this boat new and I have over 123 hours on it. I am looking to upgrade both midrange performance (when tubing and cruising with heavy loads) and improved fuel economy. I used to have a fishing boat and loved the 4 blade SS prop I had on it but unsure of real world performance on a pontoon. The Yamaha prop selector is of little use and it seems there are as many opinions as ... but looking for real experiences of either a 3 or 4 blade SS prop on a pontoon with similar size and with a Yamaha F90 or F115 as both use the same block.

Specs for the engine: Full throttle range 5300-6300 RPM
Specs of this boat with a light load: WOT 6200 RMPs (suggests a higher pitch but would reduce low end performance), holds plane at 3500-3600 RPMs and tops out at 31 MPH.

The boat is used for everything from large group cruising, pulling tubes and fishing. I am will to give up a little on the top end but not more than 2 MPH as I am on a large lake.

Has anyone upgraded to a 3 or 4 blade stainless steel prop with a similar boat/motor configuration and if so which one?

Thanks

Hey. What did you end up doing with you prop. Did you buy a 3-4 blade. Did it help ?

 

[PinnacleG23]

I currently run a 16P Enerita. Excellent prop, but getting some slip with this boat in the mid-range, which I didn't get with my G23. I tried a aluminum blackmax 16x16. Interestingly it was similar to the enerita until 3600RPM, then it fell off the edge and the Enerita keep getting better and holding all the way to WOT.
I tried a 15.5x17 Mirage Plus, another great prop, similar to the Yamaha SWS. Its was OK, but again doesn't bite and hold like the enerita. Next week I'm trying a Powertech 15.5x15 OFS4 four blade. I'll post the specific results of all the props next week. If the four blade isn't better than the enerita in the midrange, I'm going to raise my engine one hold and stay with the enerita.

I live between 3000-4600 about 90% of the time, so I"m ok giving up a few MPH at the top end if the four blade gives me better mid-range numbers. I'm looking for slip numbers in the low 20s or better in the mid-range.

 

[Rssuttle]

I have a 2018 21SL pontoon (25" tubes and no lifting strakes) with a Yamaha F115 HP outboard (max for this toon). The outboard came standard with a 13.5 x 15 AL prop. I purchased this boat new and I have over 123 hours on it. I am looking to upgrade both midrange performance (when tubing and cruising with heavy loads) and improved fuel economy. I used to have a fishing boat and loved the 4 blade SS prop I had on it but unsure of real world performance on a pontoon. The Yamaha prop selector is of little use and it seems there are as many opinions as ... but looking for real experiences of either a 3 or 4 blade SS prop on a pontoon with similar size and with a Yamaha F90 or F115 as both use the same block.

Specs for the engine: Full throttle range 5300-6300 RPM
Specs of this boat with a light load: WOT 6200 RMPs (suggests a higher pitch but would reduce low end performance), holds plane at 3500-3600 RPMs and tops out at 31 MPH.

The boat is used for everything from large group cruising, pulling tubes and fishing. I am will to give up a little on the top end but not more than 2 MPH as I am on a large lake.

Has anyone upgraded to a 3 or 4 blade stainless steel prop with a similar boat/motor configuration and if so which one?

Thanks

Did you find a prop better?