Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 01-02-2015, 01:57   #1
Registered User

Join Date: Oct 2012
Location: Home for a couple of years.
Boat: Beneteau 49
Posts: 246
Flexofold size for a 2007 B49 with Yanmar 75hp and ZF30M?

Hi all,

I am looking at a 2007 Beneteau 49 with the 75hp Yanmar engine (3000-3200 max rpm) and ZF30M (2.15F, 2.64R) and the stock (I assume) fixed propeller. The markings on the propeller are not visible.

During the sea trial, the boat reached 9kn at 3500rpm (assuming the Yanmar gauge is correct). The alternator is stock. She weighs 30,000lbs.

Isn't this too high of a max RPM?

Also, Beneteau offered a 19x11 Flexofold (up to hull #87) or 18x13 (starting hull #88).

Flexofold person recommended 20x13 to reach 3000rpm or 20x12 to reach 3200rpm.

What do you think about flexofold propeller size?
What do people use and what are the speed/rpm numbers?
What would be the right prop size?

Thank you for any info.
__________________

__________________
boom23 is offline   Reply With Quote
Old 01-02-2015, 04:50   #2
Registered User
 
Kijit's Avatar

Join Date: Jun 2010
Location: Virginia
Boat: Wauquiez Centurion 41
Posts: 53
Send a message via Skype™ to Kijit
Re: Flexofold size for a 2007 B49 with Yanmar 75hp and ZF30M?

I don't know anything about that engine, and our boat and engine are quite different, but we recently put on a Flexofold prop. The recommendation of the Flexofold folks, for us anyway, seemed to be right on, and we are quite happy with it so far. Just a data point.
__________________

__________________
Gerhard
S/V KIJIT
Wauquiez Centurion 41
Kijit is offline   Reply With Quote
Old 01-02-2015, 11:55   #3
Registered User

Join Date: Oct 2012
Location: Home for a couple of years.
Boat: Beneteau 49
Posts: 246
Re: Flexofold size for a 2007 B49 with Yanmar 75hp and ZF30M?

Thank you Gerhard. It is a good data point.

I am inclined to go with the Flexofold people recommendation. I am still curious about what speed and RPM the people who got the factory option flexofold are getting. The factory option prop is 2 inches smaller in diameter, and one inch more in pitch. That's a big difference.
__________________
boom23 is offline   Reply With Quote
Old 01-02-2015, 13:02   #4
Senior Cruiser
 
Jim Cate's Avatar

Cruisers Forum Supporter

Join Date: May 2008
Location: cruising SW Pacific
Boat: Jon Sayer 1-off 46 ft fract rig sloop strip plank in W Red Cedar
Posts: 11,461
Re: Flexofold size for a 2007 B49 with Yanmar 75hp and ZF30M?

FWIW, when we installed our F-O-F, the size recommended by the folks at the dealer was exactly right, reaching the red line just at hull speed, so there's another one they got right. Re the size on the Bennie: remember that the price if those props goes up with diameter, and perhaps their decision was fiscally determined. Additional pitch does not change the price...

Jim
__________________
Jim and Ann s/v Insatiable II , lying Port Cygnet, Tasmania once again
Jim Cate is offline   Reply With Quote
Old 01-02-2015, 15:35   #5
Registered User

Join Date: Jan 2014
Posts: 25
Re: Flexofold size for a 2007 B49 with Yanmar 75hp and ZF30M?

boom,

i have the oceanis 50 with a yanmar 4JH4-TE with a SD-50. Flex-o-fold recommended the 3-Blade 20x13L.

i installed it last spring and am very happy with it. I get 9.5 kts at 3200 rpm. but am generally cruising at 6.5-7 at 2000 rpm.

mike
__________________
Mike

Beneteau Oceanis 50
MickBeth50 is offline   Reply With Quote
Old 01-02-2015, 16:02   #6
Registered User

Join Date: Oct 2012
Location: Home for a couple of years.
Boat: Beneteau 49
Posts: 246
Re: Flexofold size for a 2007 B49 with Yanmar 75hp and ZF30M?

Quote:
Originally Posted by MickBeth50 View Post
boom,

i have the oceanis 50 with a yanmar 4JH4-TE with a SD-50. Flex-o-fold recommended the 3-Blade 20x13L.

i installed it last spring and am very happy with it. I get 9.5 kts at 3200 rpm. but am generally cruising at 6.5-7 at 2000 rpm.

mike
Mike,
the SD50 has 2.32 reduction ratio forward and reverse. This indicates to me that since I have 2.15 reduction forward, the 20x13-3L will be too much for me.
Thanks for the info.

P.S. Keep an eye on the SD50. Once you get a hint of clutch slipping, get the cone clutch re-lapped or replaced.
__________________
boom23 is offline   Reply With Quote
Old 01-02-2015, 17:59   #7
Registered User

Join Date: Oct 2012
Location: Home for a couple of years.
Boat: Beneteau 49
Posts: 246
Re: Flexofold size for a 2007 B49 with Yanmar 75hp and ZF30M?

I used a prop calculation program to figure out the difference in prop size/pitch between 2.32 (Mike's SD50) and 2.15 (ZF30M).

The difference is only 1" in pitch.

So, it seems that the Flexofold people recommendation for a 20x12-3R will be just right to achieve 3200rpm!
__________________
boom23 is offline   Reply With Quote
Old 02-02-2015, 11:01   #8
Senior Cruiser

Cruisers Forum Supporter

Join Date: Sep 2007
Location: Enkhuizen, NL
Boat: Pearson 36-1
Posts: 330
Send a message via Skype™ to George DuBose
Re: Flexofold size for a 2007 B49 with Yanmar 75hp and ZF30M?

Hello CruisersForum,

Diameter and pitch are a mystery to me. At least to understand which combination would be best for my boat and motor.

When I bought my FOF 2-blade, the salesman just asked me the make of my engine. The original blades wouldn't close because they hit the skeg.

The Flex-o-Fold blades I have now are 15x13 RH. I lost an inch of pitch from the original fixed bladed prop.

Any comments?

Thanks,



George DuBose,
Thank you for your email.
Unfortunately, we can´t offer you the propeller size requested (15x14R).
This as the diameter/pitch is not a good propeller combination.

Best regards,
Keld Willberg
Sales & Marketing Manager


Flexofold ApS
Bramdrupvej 50
DK-6040 Egtved
Tel. +45 75 55 43 46
Fax +45 75 55 43 66

Folding Propellers - Flexofold





-----Oprindelig meddelelse-----
Fra: George DuBose [mailto:boss@george-dubose.com]
Sendt: 1. december 2014 18:54
Til: Keld Willberg
Emne: question

Dear Mr. Willberg,

In 2012, I purchased a Flexofold two bladed propellor from your firm directly.

At the Boot in Düsseldorf, the salesman just asked me for my engine and transmission data and delivered to me:

1613R/16-78 (€922,00) for my:

1973 Pearson 36-1
Weight 13500 lbs. - 6.123497 metric tons Engine - Yanmar 3GM30F Transmission is a Kanzaki KM2P with a reduction gear ratio of 2.62 Prop shaft diameter 7/8 inch or 22.225mm Threaded section of shaft reduced to 5/8 inch or 17.145mm The hub of the existing propeller is 65mm long The shaft is removed from the boat, the "key" and keyway are 1/4" or 6.35mm

The 16" blades as delivered could not close due to the skeg before the rudder. You kindly swapped the 16" blades for 15" blades and they fit fine.

However, over the past two years that I have used my boat with the Flex-o-Fold, I have come to realize that I have lost a knot from my former speed (7 down to 6 kts). The fixed prop that was replaced was a
15x14 RH. The Flex-o-Fold blades I have now are 15x13 RH.

In the interest of getting better fuel consumption and perhaps some of my speed back when powering, I am asking your advice about getting a pair of 15x14 RH blades from you.

Thank you for your time.
__________________
George DuBose is offline   Reply With Quote
Old 03-02-2015, 01:22   #9
Registered User

Join Date: Apr 2012
Location: Holland
Boat: Leisure 27
Posts: 4
Re: Flexofold size for a 2007 B49 with Yanmar 75hp and ZF30M?

Try this program: Vicprop - Prop calculator for Displacement and semi-displacement hulls
It gives quite precise results .
Ad
__________________
YellowBoat is offline   Reply With Quote
Old 16-02-2015, 08:46   #10
Registered User

Join Date: Sep 2014
Posts: 22
Re: Flexofold size for a 2007 B49 with Yanmar 75hp and ZF30M?

I've had Flexofold props on my last two boats and went with their recommended size. However it should be sized to reach the maximum engine RPMs. My Yanmar 50 HP is rated at 3600 and I can reach that at flank speed. Another recent change from Yanmar is they recommend a cruising RPM at 80% of maximum rather than 75%.

Capt Morgan
__________________
Captn morgan is offline   Reply With Quote
Old 16-02-2015, 11:19   #11
Registered User

Join Date: Oct 2012
Location: Home for a couple of years.
Boat: Beneteau 49
Posts: 246
Re: Flexofold size for a 2007 B49 with Yanmar 75hp and ZF30M?

I believe the Yanmar 4JH4-TE 75hp is rated at 3200rpm.
__________________
boom23 is offline   Reply With Quote
Old 17-02-2015, 07:02   #12
Registered User

Join Date: Sep 2014
Posts: 22
Re: Flexofold size for a 2007 B49 with Yanmar 75hp and ZF30M?

Mine is the 4JHE. I was just pointing out that no matter the engine size the correct prop will allow you to achieve the maximum engine rpms.

Captn Morgan
__________________

__________________
Captn morgan is offline   Reply With Quote
Reply

Tags
beneteau, factory, flexofold, option, propeller, size, yanmar

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Yanmar 75hp 2007 info Williamp Engines and Propulsion Systems 11 29-08-2012 03:47
Nissan Chrysler 75hp Marine Diesel CharlieCobra Vendor Spotlight - Great Deals for CF Members! 0 05-11-2011 07:29
Changing Zinc on Flexofold Prop dpollitt Propellers & Drive Systems 9 23-03-2010 08:32
I need input on a "Flexofold" prop Big Moe General Sailing Forum 3 23-02-2009 21:50



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 22:59.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.