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New Yamaha Prop - SWS II HP

Potomacbassin’

Potomacbassin’

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Interesting, might be worth a try! According to their description of boats, my new tri-toon should fall in that category
 
Your SHO should be able to push that - my F250 comes up a little short of max RPM with a 17p but I would assume running 89 you might have a little more HP.

Interestingly both the old SWS and new HP are running equal diameter for 18p, so the re-design must be in the ear shape or rake. I can't quite tell but looks like the HP has less blade area. Pics are individual and overlaid.

6E575108-FA69-483B-A3D9-EE082E56691A.jpegB08B9097-3D28-4E31-95E5-85B32BB93067.jpegC23D8EB9-B1DA-4079-8EA5-9CA9E9823EEF.jpeg
 
The Hillbilly Barge said:
I have a 14.25 18p now and I'm not a fan
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Out of curiosity what are you not happy about?

I think your issue is diameter - there is now way with the weight of your G series and 300HP that 14.25 is giving you optimal efficiency. I'm guessing 47mph at 6200 RPM, which gives you 22% slip. Pretty bad.

You need more blade area. My guess is you should be able to hit 50 if not better lightly loaded.
 
It's 47 mph at 5500 rpm and about 12% slippage, that's still on the high side, I'm not convinced the rpms aren't limited, you can adjust the trim anyway you want and not exceed 5500 rpms, this is my first outboard so I have very little experience with them, I bought this boat late in the season and have put about 15 minutes of time on it
 
Jb75 said:
I’m guessing that is a reliance prop? I think that is your problem. 250/300 need the swsII or go enertia/hub change and I think you’ll be happier
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I would normally agree but I don't understand the low RPM. Dealer put a crappy 17p Reliance on my 250 and I could max RPM at 6200 and still had about 5-8 degrees of throttle left. There is something else amiss. Definitely agree that an Enertia prop would be the way to go.
 
The Hillbilly Barge said:
It's 47 mph at 5500 rpm and about 12% slippage, that's still on the high side, I'm not convinced the rpms aren't limited, you can adjust the trim anyway you want and not exceed 5500 rpms, this is my first outboard so I have very little experience with them, I bought this boat late in the season and have put about 15 minutes of time on it
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I remember this from another thread, something definitely limiting your RPM and I'd be shocked if it was the prop. Hopefully you get some time in the chair and dealership to get this figured out, I'd be unhappy with those performance numbers as well. Good news is no where to go but up!
 
Potomacbassin’ said:
I would normally agree but I don't understand the low RPM. Dealer put a crappy 17p Reliance on my 250 and I could max RPM at 6200 and still had about 5-8 degrees of throttle left. There is something else amiss. Definitely agree that an Enertia prop would be the way to go.
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I agree to a point. Although 14.25 is a little on the small side an 18p prop spinning at 5500 on a hull like ours is not too shabby. I’ve run a 15 1/4 by 18p and a 151/2 by 17 solas and couldn’t really turn either past 5400(18) and 55/5600 (17). Can bounce my 151/2 by 16 off the rev limiter. Weird I know but unless you take you prop to a prop shop abs get it measured and fine tuned they are a relative pitch. Maybe his 18 is more like 19? I’ve come to live with the fact that these boats with a 250/300 Yamaha will run high 40’s to very low 50’s no matter what I change. I’ve also raised the motor And chipped the ECU. I’m sick I know
 
Worth emphasising that the bay boat in the link above is both lighter and designed for more speed (shallow draft) than any of the pontoons in this thread (so far). The 19p comparison does show a top end gain of 1.6 MPH, but I saw no mention of other performance data. Anyway, as also noted above in this class of pontoon, 50 HP can disappear pretty quickly with limited effect. Looks like the SWS HP design pushes it toward the Enertia....?
 
Jb75 said:
I agree to a point. Although 14.25 is a little on the small side an 18p prop spinning at 5500 on a hull like ours is not too shabby. I’ve run a 15 1/4 by 18p and a 151/2 by 17 solas and couldn’t really turn either past 5400(18) and 55/5600 (17). Can bounce my 151/2 by 16 off the rev limiter. Weird I know but unless you take you prop to a prop shop abs get it measured and fine tuned they are a relative pitch. Maybe his 18 is more like 19? I’ve come to live with the fact that these boats with a 250/300 Yamaha will run high 40’s to very low 50’s no matter what I change. I’ve also raised the motor And chipped the ECU. I’m sick I know
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I've considered going the ECU flash route, but these walls may have ears...

My F250 could push a 15.25 x 19p to 5300 RPM, so combined with less pitch and much less diameter that's why I'm surprised the 18p could only muster 5500. But prop change will answer a lot for HillBilly.

I have read that pitch is relative to the OEM's and not apples to apples so agree there as well. I don't think we know what brand that prop is, but if Solas that could also be part of the answer... sounds like for our heavy boats Merc and Yam have much better designs.
 
I'm also surprised by the rpm limitations with a 14.25 prop. My particular engine runs through a simrad with no other gauges or information available, I'm completely new to outboard motors and haven't owned a boat in 30 years so the electronics are new to me, can you set the rpm limitations with the simrad, the engine only has 50 hours and seems to run well so I don't think it's wounded
 
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The Hillbilly Barge said:
I'm also surprised by the rpm limitations with a 14.25 prop. My particular engine runs through a simrad with no other gauges or information available, I'm completely new to outboard motors and haven't owned a in 30 years so the electronics are new to me, can you set the rpm limitations with the simrad, the engine only has 50 hours and seems to run well so I don't think it's wounded
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I don't think you can, it's likely a one-way signal from the engine bus to your Simrad, but certainly a question for your Yamaha tech. It's possible that everything is actually reading and operating correctly so trying another prop should be a huge help in triangulating (so to speak) what could be going on. Please keep us posted on any updates!
 
Potomacbassin’ said:
Not sure if this was covered in another thread, but just saw this in my inbox. New Yamaha prop that apparently is designed to bias towards top end speed. I did notice the lowest pitch is 18 so it might not be applicable to most of us, but thought I'd pass along.

Thanks

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Thanks Alot Potomacbassin'

I had not seen anything on this and it could very well be my perfect prop.

I'm guessing they finally built us an Enertia with slightly more diameter And SDS!

Bravo Yamaha!

edit: Backordered till 6/10 - Oh well it should be worth the wait.
 
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JDB said:
Thanks Alot Potomacbassin'

I had not seen anything on this and it could very well be my perfect prop.

I'm guessing they finally built us an Enertia with slightly more diameter And SDS!

Bravo Yamaha!

edit: Backordered till 6/10 - Oh well it should be worth the wait.
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That is fantastic! Hope it turns out to be a good alternative for some higher HP toons. Please post some results when you get some seat time under it!
 
A quick update on this back ordered prop that was delayed an additional 2 months after the first 3 month delay!

My 19" and 20" versions are finally scheduled to arrive tomorrow 08/09 and I will post pics of one next to an inertia for comparison followed by lake testing hopefully in a couple of weeks.

It appears that all of the current batch are sold as they are again showing back ordered on Crowley Marine's Site.
 
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