21mph at 6000 or 22mph at 5100rpm?

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Otisville
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Joined: Mon Jul 31, 2017 11:16 am

21mph at 6000 or 22mph at 5100rpm?

#1 Post by Otisville » Thu Aug 31, 2017 5:37 pm

Is it better to go 22mph at 5100 or 21mph at 6k rpm? The difference between a 14. 11 and a 14. 13 pitch. I have a 2004 50 horse Yamaha on a 2019re sweetwater.
[b]2005 Sweetwater 2019 RE [/b]
[i]Yamaha 50 4 stroke[/i]

captain28570
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Location: Baton Rouge LA

Re: 21mph at 6000 or 22mph at 5100rpm?

#2 Post by captain28570 » Thu Aug 31, 2017 5:51 pm

I would say you need a 12 pitch prop. Get the rpms around 5500. Whats the max rpm on the motor? 2 or 4 stroke?
2017 22 Manitou Aurora LE SHP Tritoon Evinrude G2 HO 150

Otisville
Posts: 11
Joined: Mon Jul 31, 2017 11:16 am

Re: 21mph at 6000 or 22mph at 5100rpm?

#3 Post by Otisville » Thu Aug 31, 2017 5:58 pm

Manufacturer says optimum mom is 5K to 6K and it's a four stroke.
[b]2005 Sweetwater 2019 RE [/b]
[i]Yamaha 50 4 stroke[/i]

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ROLAND
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Re: 21mph at 6000 or 22mph at 5100rpm?

#4 Post by ROLAND » Fri Sep 01, 2017 1:56 am

I have a yamaha 75 four stroke.. and I believe the specs show the rev alarm will sound at approx. 6200 rpm's. My boat wide open is turning just a hair under 6K rpm's.... A few years back I changed props and she topped out at around 5K rpm's and the guys on this forum told me I was over propped... So I went back to my original prop where she runs about 23 mph just under 6K. Hope this helps.
Roland & Jo
2010 Bennington 20 Sfi
Yamaha 75 4 Stroke
Shreveport, Louisiana

Otisville
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Re: 21mph at 6000 or 22mph at 5100rpm?

#5 Post by Otisville » Fri Sep 01, 2017 6:31 am

What did you do with the prop? Can they be returned? No blemishes on mine. Used once.
[b]2005 Sweetwater 2019 RE [/b]
[i]Yamaha 50 4 stroke[/i]

captain28570
Posts: 85
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Location: Baton Rouge LA

Re: 21mph at 6000 or 22mph at 5100rpm?

#6 Post by captain28570 » Fri Sep 01, 2017 6:54 pm

Yea close to 6000 as you can get it with a light load. Toons are harder to get max rpms out of them. You lug the engine if you only turning 5100 rpms.
2017 22 Manitou Aurora LE SHP Tritoon Evinrude G2 HO 150

DWRAT
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Re: 21mph at 6000 or 22mph at 5100rpm?

#7 Post by DWRAT » Fri Sep 01, 2017 9:31 pm

I can tell you that at 5,100 rpms you are saving gas big time over 6,000 rpms.
I would only run the smaller prop for when you have 10 people on your boat.
BTW, I have the exact same situation on my Merc 150 and base my info off my Mercury smart craft gauge.
2012 SouthBay 722CRO 115hp Merc 4-stroke. Edit, make that a 150hp Merc 4-stroke now.

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ROLAND
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Re: 21mph at 6000 or 22mph at 5100rpm?

#8 Post by ROLAND » Sat Sep 02, 2017 1:09 am

[quote="Otisville"]What did you do with the prop? Can they be returned? No blemishes on mine. Used once.[/quote]

I returned it to marine shop where I bought it. Called him up and told him how the new prop was only cranking out about 5k rpm's and told him I wanted to go back to the original pitch prop. He ordered me a new one and it was at his shop like 3 days later..
Roland & Jo
2010 Bennington 20 Sfi
Yamaha 75 4 Stroke
Shreveport, Louisiana

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jrolin1
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Location: Lexington SC Lake Murray

Re: 21mph at 6000 or 22mph at 5100rpm?

#9 Post by jrolin1 » Sat Sep 02, 2017 4:55 am

Make sure your motor height is correct. If it is not you get strange results with different props.

Otisville
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Re: 21mph at 6000 or 22mph at 5100rpm?

#10 Post by Otisville » Sat Sep 02, 2017 2:13 pm

What is the simple science of engine height? How I check? The engine has been at the same height for years. Thx
[b]2005 Sweetwater 2019 RE [/b]
[i]Yamaha 50 4 stroke[/i]

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toondog
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Re: 21mph at 6000 or 22mph at 5100rpm?

#11 Post by toondog » Sun Sep 03, 2017 9:09 am

It's a good idea to have a spare prop along with hardware and floating prop wrench. 5100 rpm is a little low though.
96 20 special Grumman 50hp evinrude
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jrolin1
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Re: 21mph at 6000 or 22mph at 5100rpm?

#12 Post by jrolin1 » Sun Sep 03, 2017 11:20 am

[quote="Otisville"]What is the simple science of engine height? How I check? The engine has been at the same height for years. Thx[/quote]

[img]http://i67.photobucket.com/albums/h307/ ... olow-1.jpg[/img]
http://nodakangler.com/forums/showthrea ... ine-height

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