Date   

Re: [Amel Yacht Owners] Onan genset trouble code "seven blinks"

Thomas Peacock
 

We have had similar, recurrent problems on our SM #240. For some reason, the impellers we buy for the Onan have a tendency to lose blades, which then get trapped. By comparison, we have not noted that with the Volvo drive engine. 

One thing I have noticed: even when the engines (either Onan or Volvo) are not putting out sufficient water, there is a “throaty” exhaust sound. 

Even better, which I don’t think I can pass on, is what happened when I had an expert on board to look at a water flow issue. He put his hand on the side of the Onan, just downstream of the impeller, felt the surface for a couple of seconds, and diagnosed the problem immediately.

But you’re right, the fix is well within anyone’s skills who follows this Amel site.

Tom Peacock
SM #240 Aletes
Falmouth Harbour, Antigua

On Dec 16, 2017, at 9:21 PM, john.biohead@... [amelyachtowners] <amelyachtowners@...> wrote:


Hi All,

  I case anyone has not seen this before.  Started the Onan 7KW generator after a passage and it turned off shortly after starting.  It gave the seven blinking light trouble code.  My manual indicates this is the “no sea water flow” shutdown.   Don't force the generator to run if you get this code and there is no sea water coming out of the exhaust, like the situation we were in tonight.

 

Checked the obvious sea strainer all good, then broke out tools  to open up the sea water pump and discovered only two vanes left on the impeller.  Installed the onboard ready spare (you should have at least one spare all the time)  but on restart continued to get the no flow shutdown.  Pump was full of water and all vanes aligned correctly.  Checked down stream and found the heat exchanger inlet plugged with …..you guessed it, impeller vanes.   After clearing all the debris and repriming the sea water system the genset is back on line. 

Note, all these steps were rather simple, just a bit tedious.  The pump was easy to open, impeller pulled right out.  New one was a bit of a four letter pushing match to get into the housing but eventually my thumbs won.  The heat exchanger had one bolt to remove the end cap and then used tweezers to pull out the bits of impeller plugging the heat exchanger.    Will post pictures on the FB page. 

 

Take home message, onboard spares, and “yes you can do it yourself with a little patience and common sense.  This repair cost us one impeller, ($30USD)  and 1.5hr labor.  How much would an Onan technician charge us for this repair?  

 

                   Regards,  John

 

John Clark

SV Annie  SM 37


Just moored at St.  Augustine for Christmas





hatch gaskets

JEFFREY KRAUS
 

Good Morning Amelians,

I need to change the gaskets on the forward hatches. 

I did the saloon hatch a couple years ago, and seem to remember the gasket was a 1 piece gasket that I got from lewmar. 

I believe the OD dimensions on the 2 hatches are 22.5" by 22.5" and 20.5" by 22.5" . 

They are lewmar low profile hatches, but I'm not sure of the model #.

If anyone has the kit # or model # to help me order the gaskets, I would be greatly appreciative.

Jeff

Spirit Amel 54 #14


Re: Amel Santorin Propeller Question

Ian Park
 

Lisa
The transmission on the Santorin is the same as the Super Maramu, well the big ‘C’ drive.
I presume you have the Perkins Prima M50? They have a Hurth gearbox between the Drive and the engine, and I believe both forward and reverse gears have separate clutches. Have you checked the gearbox oil level? The dipstick must be used NOT screwed in, but with the thread just sitting at the top of the aperture otherwise you can over fill it.
I had to have mine replaced in Marin a couple of years ago. The Amel engine mechanic is very good.
We’ll be in Marin over Christmas and New Year getting our outhaul gearbox separated from the boom plus a few other rigging issues. Then on to Antigua - we’ll look out for you.

Ian and Linda
Ocean Hobo. SN96 currently in Bequia


Re: [Amel Yacht Owners] Onan genset trouble code "seven blinks"

Bill & Judy Rouse <yahoogroups@...>
 

John 

Don't look too hard for the water flow sensor that Eric spoke about. If your Onan is original and if nobody added one and also changed the PCB, you will not have one. 

I am not sure of the year this was added, but it certainly wasn't included with your generation of Onan. 

All SM are not equal. 


CW Bill Rouse
Admiral, Texas Navy
Commander Emeritus
Amel School www.amelschool.com
720 Winnie St
Galveston Island, TX 77550
+1(832) 380-4970

   

On Dec 16, 2017 22:34, "'sailormon' kimberlite@... [amelyachtowners]" <amelyachtowners@...> wrote:
 

Hi John,

There is also a sensor in the intake water hose to the raw water pump. The hole in the sensor is small and frequently becomes clogged with rust, It is easy to remove, it just unscrews. It is something to check .

Yo will see it mounted to a piece of pipe in the seawater hose.

Fair Winds

Eric

Kimberlite Amel Super Maramu #376

 

 

From: amelyachtowners@yahoogroups.com [mailto:amelyachtowners@yahoogroups.com]
Sent: Saturday, December 16, 2017 9:22 PM
To: amelyachtowners@yahoogroups.com
Subject: [Amel Yacht Owners] Onan genset trouble code "seven blinks"

 

 

Hi All,

  I case anyone has not seen this before.  Started the Onan 7KW generator after a passage and it turned off shortly after starting.  It gave the seven blinking light trouble code.  My manual indicates this is the “no sea water flow” shutdown.   Don't force the generator to run if you get this code and there is no sea water coming out of the exhaust, like the situation we were in tonight.

 

Checked the obvious sea strainer all good, then broke out tools  to open up the sea water pump and discovered only two vanes left on the impeller.  Installed the onboard ready spare (you should have at least one spare all the time)  but on restart continued to get the no flow shutdown.  Pump was full of water and all vanes aligned correctly.  Checked down stream and found the heat exchanger inlet plugged with …..you guessed it, impeller vanes.   After clearing all the debris and repriming the sea water system the genset is back on line. 

Note, all these steps were rather simple, just a bit tedious.  The pump was easy to open, impeller pulled right out.  New one was a bit of a four letter pushing match to get into the housing but eventually my thumbs won.  The heat exchanger had one bolt to remove the end cap and then used tweezers to pull out the bits of impeller plugging the heat exchanger.    Will post pictures on the FB page. 

 

Take home message, onboard spares, and “yes you can do it yourself with a little patience and common sense.  This repair cost us one impeller, ($30USD)  and 1.5hr labor.  How much would an Onan technician charge us for this repair?  

 

                   Regards,  John

 

John Clark

SV Annie  SM 37

Just moored at St.  Augustine for Christmas

 


Re: [Amel Yacht Owners] Onan genset trouble code "seven blinks"

Mark Erdos
 

What goes in must come out.

 

A couple of helpful hints:

Use dish washing soap to install new impellers. Also the added benefit, when you see bubbles off the side of the boat you know the sea water is flowing.

 

You can also us a shop-vac to remove the impeller blade bits from the heat exchanger.

 

Impeller blade alignment at install doesn’t matter. The impeller will self adjust the blades on the first rotation.

 

I installed an in-line filter between the water pump and the heat exchanger to trap debris from the impeller.

 

 

 

 

With best regards,

 

Mark

 

Skipper

Sailing Vessel - Cream Puff - SM2K - #275

Currently cruising - Martinique

www.creampuff.us

 

From: amelyachtowners@... [mailto:amelyachtowners@...]
Sent: Saturday, December 16, 2017 10:22 PM
To: amelyachtowners@...
Subject: [Amel Yacht Owners] Onan genset trouble code "seven blinks"

 

 

Hi All,

  I case anyone has not seen this before.  Started the Onan 7KW generator after a passage and it turned off shortly after starting.  It gave the seven blinking light trouble code.  My manual indicates this is the “no sea water flow” shutdown.   Don't force the generator to run if you get this code and there is no sea water coming out of the exhaust, like the situation we were in tonight.

 

Checked the obvious sea strainer all good, then broke out tools  to open up the sea water pump and discovered only two vanes left on the impeller.  Installed the onboard ready spare (you should have at least one spare all the time)  but on restart continued to get the no flow shutdown.  Pump was full of water and all vanes aligned correctly.  Checked down stream and found the heat exchanger inlet plugged with …..you guessed it, impeller vanes.   After clearing all the debris and repriming the sea water system the genset is back on line. 

Note, all these steps were rather simple, just a bit tedious.  The pump was easy to open, impeller pulled right out.  New one was a bit of a four letter pushing match to get into the housing but eventually my thumbs won.  The heat exchanger had one bolt to remove the end cap and then used tweezers to pull out the bits of impeller plugging the heat exchanger.    Will post pictures on the FB page. 

 

Take home message, onboard spares, and “yes you can do it yourself with a little patience and common sense.  This repair cost us one impeller, ($30USD)  and 1.5hr labor.  How much would an Onan technician charge us for this repair?  

 

                   Regards,  John

 

John Clark

SV Annie  SM 37

Just moored at St.  Augustine for Christmas

 


Re: [Amel Yacht Owners] Onan genset trouble code "seven blinks"

eric freedman
 

Hi John,

There is also a sensor in the intake water hose to the raw water pump. The hole in the sensor is small and frequently becomes clogged with rust, It is easy to remove, it just unscrews. It is something to check .

Yo will see it mounted to a piece of pipe in the seawater hose.

Fair Winds

Eric

Kimberlite Amel Super Maramu #376

 

 

From: amelyachtowners@... [mailto:amelyachtowners@...]
Sent: Saturday, December 16, 2017 9:22 PM
To: amelyachtowners@...
Subject: [Amel Yacht Owners] Onan genset trouble code "seven blinks"

 

 

Hi All,

  I case anyone has not seen this before.  Started the Onan 7KW generator after a passage and it turned off shortly after starting.  It gave the seven blinking light trouble code.  My manual indicates this is the “no sea water flow” shutdown.   Don't force the generator to run if you get this code and there is no sea water coming out of the exhaust, like the situation we were in tonight.

 

Checked the obvious sea strainer all good, then broke out tools  to open up the sea water pump and discovered only two vanes left on the impeller.  Installed the onboard ready spare (you should have at least one spare all the time)  but on restart continued to get the no flow shutdown.  Pump was full of water and all vanes aligned correctly.  Checked down stream and found the heat exchanger inlet plugged with …..you guessed it, impeller vanes.   After clearing all the debris and repriming the sea water system the genset is back on line. 

Note, all these steps were rather simple, just a bit tedious.  The pump was easy to open, impeller pulled right out.  New one was a bit of a four letter pushing match to get into the housing but eventually my thumbs won.  The heat exchanger had one bolt to remove the end cap and then used tweezers to pull out the bits of impeller plugging the heat exchanger.    Will post pictures on the FB page. 

 

Take home message, onboard spares, and “yes you can do it yourself with a little patience and common sense.  This repair cost us one impeller, ($30USD)  and 1.5hr labor.  How much would an Onan technician charge us for this repair?  

 

                   Regards,  John

 

John Clark

SV Annie  SM 37

Just moored at St.  Augustine for Christmas

 


Re: [Amel Yacht Owners] Re: Amel Santorin Propeller Question

eric freedman
 

Liasa,

I do not know anything about the transmission on a SN.

However the last thing in the drive chain is the transmission.

My guess I that your transmission is slipping.

I would have someone look into that.

Fair Winds

Eric

Kimberlite Amel Super Maramu #376

 

 

From: amelyachtowners@... [mailto:amelyachtowners@...]
Sent: Saturday, December 16, 2017 5:24 PM
To: amelyachtowners@...
Subject: [Amel Yacht Owners] Re: Amel Santorin Propeller Question

 

 

Thanks Craig. We’ve been investigating all day. Nothing on the prop and it looks good and clean. No black smoke or any other symptoms coming from the engine. The prop spins while we are looking at it but after a few hours of motoring, does not seem to be able to handle going into any wind or waves. Wondering if it may be a gearbox oil issue? That maybe it shuts down as it heats up? Baffled at the moment.
Thanks for the response!
Lisa


Onan genset trouble code "seven blinks"

John Clark
 

Hi All,

  I case anyone has not seen this before.  Started the Onan 7KW generator after a passage and it turned off shortly after starting.  It gave the seven blinking light trouble code.  My manual indicates this is the “no sea water flow” shutdown.   Don't force the generator to run if you get this code and there is no sea water coming out of the exhaust, like the situation we were in tonight.

 

Checked the obvious sea strainer all good, then broke out tools  to open up the sea water pump and discovered only two vanes left on the impeller.  Installed the onboard ready spare (you should have at least one spare all the time)  but on restart continued to get the no flow shutdown.  Pump was full of water and all vanes aligned correctly.  Checked down stream and found the heat exchanger inlet plugged with …..you guessed it, impeller vanes.   After clearing all the debris and repriming the sea water system the genset is back on line. 

Note, all these steps were rather simple, just a bit tedious.  The pump was easy to open, impeller pulled right out.  New one was a bit of a four letter pushing match to get into the housing but eventually my thumbs won.  The heat exchanger had one bolt to remove the end cap and then used tweezers to pull out the bits of impeller plugging the heat exchanger.    Will post pictures on the FB page. 

 

Take home message, onboard spares, and “yes you can do it yourself with a little patience and common sense.  This repair cost us one impeller, ($30USD)  and 1.5hr labor.  How much would an Onan technician charge us for this repair?  

 

                   Regards,  John

 

John Clark

SV Annie  SM 37

Just moored at St.  Augustine for Christmas



Re: [Amel Yacht Owners] Re: Amel Santorin Propeller Question

Porter McRoberts
 

I just was plagued by the exact scenario.
Make sure the transmission fluid dipstick has an excellent seal.
And my issue: i had changed the filter and thought i’d seated the filter cap well, but hadn’t.  a small vacuum leak occurred once pressure built and then over time the pressure would drop, thered be mechanical uncoupling sand slipping of the transmission and also the brake caliper would gradually close onto the rotor.  

Hope this helps.  Have the transmission pressure tested—at the time of the failure, as it would be normal during functional operation.

Porter McRoberts
S/V Ibis: Amel 54-#152
Ft. Lauderdale
www.fouribis.com
portermcroberts@...







On Dec 16, 2017, at 5:53 PM, James Alton lokiyawl2@... [amelyachtowners] <amelyachtowners@...> wrote:

Lisa,


  I am just guessing but it is possible that the transmission on the engine is beginning to slip.  How does the transmission oil look?   Also is the transmission running hot when this problem occurs?   The transmission would see increased loading during wind/ waves and might not slip at lower power settings so if it is getting weak this is when the problem would tend to show itself.   If the transmission is slipping a lot it might be possible to see if the output shaft from the transmission is increasing in RPM as it should as the throttle is advanced during a period when you seem to be losing thrust.  Again just totally guessing but I have experienced a slipping transmission on one boat and it behaved a bit like this.

Best of luck,

James
SV Sueno,  Maramu #220

On Dec 16, 2017, at 6:24 PM, lisallt2@... [amelyachtowners] <amelyachtowners@...> wrote:

Thanks Craig. We’ve been investigating all day. Nothing on the prop and it looks good and clean. No black smoke or any other symptoms coming from the engine. The prop spins while we are looking at it but after a few hours of motoring, does not seem to be able to handle going into any wind or waves. Wondering if it may be a gearbox oil issue? That maybe it shuts down as it heats up? Baffled at the moment. 
Thanks for the response!
Lisa





Re: [Amel Yacht Owners] Re: Amel Santorin Propeller Question

James Alton
 

Lisa,

  I am just guessing but it is possible that the transmission on the engine is beginning to slip.  How does the transmission oil look?   Also is the transmission running hot when this problem occurs?   The transmission would see increased loading during wind/ waves and might not slip at lower power settings so if it is getting weak this is when the problem would tend to show itself.   If the transmission is slipping a lot it might be possible to see if the output shaft from the transmission is increasing in RPM as it should as the throttle is advanced during a period when you seem to be losing thrust.  Again just totally guessing but I have experienced a slipping transmission on one boat and it behaved a bit like this.

Best of luck,

James
SV Sueno,  Maramu #220

On Dec 16, 2017, at 6:24 PM, lisallt2@... [amelyachtowners] <amelyachtowners@...> wrote:

Thanks Craig. We’ve been investigating all day. Nothing on the prop and it looks good and clean. No black smoke or any other symptoms coming from the engine. The prop spins while we are looking at it but after a few hours of motoring, does not seem to be able to handle going into any wind or waves. Wondering if it may be a gearbox oil issue? That maybe it shuts down as it heats up? Baffled at the moment. 
Thanks for the response!
Lisa



Re: Amel Santorin Propeller Question

Azimuth
 

Thanks Craig. We’ve been investigating all day. Nothing on the prop and it looks good and clean. No black smoke or any other symptoms coming from the engine. The prop spins while we are looking at it but after a few hours of motoring, does not seem to be able to handle going into any wind or waves. Wondering if it may be a gearbox oil issue? That maybe it shuts down as it heats up? Baffled at the moment.
Thanks for the response!
Lisa


Re: [Amel Yacht Owners] Weight distributuion

James Alton
 

Bill,

   Thanks for your input and opinion.  It seems that most of the Amels that I have seen to date seem to be down by the stern at least some but on the other hand I don’t hear many complaints about handling or performance.  Perhaps as you allude the Amel hull is not too sensitive to fore/aft trim changing those parameters?    That would certainly be a desirable trait to have on a cruising hull but not something that I have studied or thought about much so far...   You make a good point about the shallow bows of some boats  being must more sensitive to fore/aft trim changes than the deeper Amel bow.  The (by todays standards) relatively sharp and deep bow entry of the Amel is one of the things that I really like about the hull design as it seems to eliminate much of the pounding as compared to a more flatish entry.

    I like the way my boat handles the way she is  (very slightly down by the stern) and want to do my best to not mess that up by altering the weight distribution and changing the fore/aft trim of the boat in an unfavourable direction.  My testing in light conditions with no sail up shows that the boat has only a very slight tendency for the bow to blow off which to me means that the boat will be under control at low speeds while maneuvering and so far that is how it has worked out.  The bow also does not blow off after a slow tack as many other boats I have sailed do which is important in the event that I am ever forced to tack in a critical area, perhaps with no engine as a backup.  I found that while coasting along with no sail up I could continue to turn the boat towards the eye of the wind down to about 1/10 of a knot of boat speed in light air conditions.  I feel that this type of balance is really nice in gusty conditions since the boat tends to not be directionally affected much by the gusts giving me one less thing to worry about.  Depressing the stern further would increase windage forward and reduce it aft while also moving the CLR aft, all of  which will combine to increase the tendency for the bow to blow off at low speeds, hence my concern.    On the other hand the windage of an arch would be a little like having some mizzen out and tend to hold the bow up an might compensate for some or even all of the fore/aft trim change due to adding the arch.  I guess one could try to work some of this out mathematically but sometimes  the only way to know for sure  is to make the actual change and live with it.  So this is why I am trying to gather as much information as I can before committing to a particular arch design,  thanks for your contribution even it if is just speculation.   

Best,

James
SV Sueno,  Maramu #220

On Dec 16, 2017, at 1:59 PM, greatketch@... [amelyachtowners] <amelyachtowners@...> wrote:

James,


I could speculate about the effect of minor changes in fore and aft trim, but it would be just that--speculation  Some boats have a very carefully calibrated bow immersion, any deeper and they wallow, and any higher they come out of the water.  I really don't think the Amel hull design is such that the line drawn on the plans is clearly better than one a tipped a little one way or the other.

When we first bought Harmonie, and she was empty of gear, she was on the waterline as drawn by Amel within a cm or so.  She rides a bit stern heavy right now.  Nothing in the way she handles indicates she has a serious problem with that.  Her helm balance is easily adjusted with sail trim. I can work her upwind easily, and she is well behaved overall.

< /div>
However...  all that said, I am not now and never have been a racing sailor tuned in to the really finer points of tweaking a boat.  I work hard and study to make her go upwind as best as I can, and pretty much figure everything else will follow along once I have that dialed in!

Bill Kinney
SM160, Harmonie
Fort Lauderdale, FL
 



Re: [Amel Yacht Owners] Weight distributuion

greatketch@...
 

James,

I could speculate about the effect of minor changes in fore and aft trim, but it would be just that--speculation  Some boats have a very carefully calibrated bow immersion, any deeper and they wallow, and any higher they come out of the water.  I really don't think the Amel hull design is such that the line drawn on the plans is clearly better than one a tipped a little one way or the other.

When we first bought Harmonie, and she was empty of gear, she was on the waterline as drawn by Amel within a cm or so.  She rides a bit stern heavy right now.  Nothing in the way she handles indicates she has a serious problem with that.  Her helm balance is easily adjusted with sail trim. I can work her upwind easily, and she is well behaved overall.

However...  all that said, I am not now and never have been a racing sailor tuned in to the really finer points of tweaking a boat.  I work hard and study to make her go upwind as best as I can, and pretty much figure everything else will follow along once I have that dialed in!

Bill Kinney
SM160, Harmonie
Fort Lauderdale, FL
 


Re: [Amel Yacht Owners] Brunswick Ga question

Courtney Gorman
 

Chuck for the bottom Lee, the Dive Guy is great his cell number 912 399 9512
Courtney
54 Trippin'

-----Original Message-----
From: clacey9@... [amelyachtowners]
To: amelyachtowners
Sent: Sat, Dec 16, 2017 12:17 pm
Subject: [Amel Yacht Owners] Brunswick Ga question

 
Hi All,
Can anyone who has stayed in Brunswick for a time recommend a boat caretaker in my absence. Someone to do the regular planned maintenance and checks. Cycle things flush the watermaker e.t.c I know the marina offers a service but want to check with anyone with past experience here. Also a diver for bottom cleaning if you have used someone you like/trust.

Regards,
Chuck
s/v Joy #388


Brunswick Ga question

Chuck_Kim_Joy
 

Hi All,

Can anyone who has stayed in Brunswick for a time recommend a boat caretaker in my absence. Someone to do the regular planned maintenance and checks. Cycle things flush the watermaker e.t.c I know the marina offers a service but want to check with anyone with past experience here. Also a diver for bottom cleaning if you have used someone you like/trust.


Regards,

Chuck

s/v Joy #388


Re: [Amel Yacht Owners] Weight distributuion

James Alton
 

Bill,

   I appreciate your speculation and think that you well might be right about spreading the weight out being a bad thing on a more modern hull.  I did however want to point out that I have good data showing that there have been boats where this method apparently worked quite well and it bothers me a bit as to why…  

  Could you speculate on whether it would better to move weight forward in the boat to be stowed under the vee berths in the forward cabin  (this is the location I was considering for the batteries)  as required to put the boat on her designed waterline versus sailing the boat with the stern down on her lines?  The boat is currently down by the stern some and I want to add an arch with as much solar as I can fit along with davits to carry the dink in protected waters. My understanding is that if the boat is down on her lines in the stern that wetted surface is increased to the detriment of light air sailing along with some other undesirable characteristics such as the tendency for the bow to blow off which I really don’t like in a boat…   

  Last year,  we put a carbon mast into a 47’ sloop that was almost 500 lbs. lighter than the severely oversized aluminum spar which had been cut down from a much larger boat.  The boat being quite narrow was fairly tender and the difference in the the sail carrying ability was nothing short of amazing.  The pitch and roll frequency went up noticeably. Sailing the old rating the boat proved unbeatable during the 2016 Chester Race Week.   The rigging wire certainly weighs more more now than the new spar so a switch to fiber could save a lot more but the rigging geometry might prohibit that change due to the shroud angles.  

Best

James

SV Sueno, Maramu #220 


On Dec 16, 2017, at 11:43 AM, greatketch@... [amelyachtowners] <amelyachtowners@...> wrote:

Danny,


I haven't done the experiment of moving heavy things from the middle of the boat out to the ends as a sailing experiment, and not sure that will every bubble up to the top of my priority list. I will be happy to speculate on the results...

I was taught that weight in the ends of the boat was always a bad thing.  That does not mean that this statement is true, but here is my thinking.  Assuming the trim of the boat stays the same, moving the weight out to the ends, as you said, increases the pitch moment of inertia.  That has a number of effects, and to my mind the most important one is it reduces the boat's natural pitch frequency.  She'll "hobbyhorse" slower--not less--just at a different frequency.

For most boats that would be a bad thing, because a "good" boat will have a pitch frequency high enough that it rarely gets triggered by waves, unless they are very short and steep.  Reducing the pitch frequency brings it into the range where it is closer to "normal" waves.  Also, with more mass, the oscillations will take more energy to stop, i.e. they will last longer. It is really amazing how quickly a boat can come to nearly a full stop when she is pitching at her natural frequency, all the energy that should be moving the boat forward, get used to just pitch her up and down.   

If we are changing the fore-and-aft trim of the boat at the same time it could get a lot more complex.

But, ultimately the dynamics we are talking about here are so complex and have so many moving parts the answer isn't easy to guess.

The only experiment I ever did that was even remotely similar was re-rigging a boat from stainless wire to dyneema--fairly dramatically reducing the roll moment of inertia.  What a difference! With reduced heel she carried full sail in 5 knots more wind, leeway was less, it just made her a better sailing boat.  And this wasn't a race boat, but a 40 foot cruising ketch.  I didn't notice a change in the roll frequency, but I didn't try to measure it either.

Bill Kinney
SM160, Harmonie
Fort Lauderdale, FL.


---In amelyachtowners@..., wrote :

Danny,

   This is an interesting area of discussion that can affect the way that we use our boats.  I understand the simplistic explanation that you provided but I think that there is quite a bit more going on and suspect that the actual data from testing might seem a little confusing when those tests are done in waves of  varying period and amplitude.  

   I know that on an older traditional design such as Olin’s Dorade that spreading out the weight can work out well.  Dorade was in fact so comfortable (and fast, the restored Dorade is in fact still doing very well racing)  that trips across the Atlantic were chosen intentionally to have the wind forward of the beam because of this fact..and because the boat rolled downwind terribly. (grin)   I think that the reason spreading the weight worked for that type of boat (under most conditions) is because the bow was very fine with little buoyancy as compared to more modern wider boats and with the pitch heavily dampened by both a heavy mast and heavy ends that the bow did not lift enough to initiate hobby horsing.  This makes for a very wet boat of course and I suspect that if the wave period happened to be close to the natural pitching moment of the boat that the weight spreading was probably not a good thing, but this is just a guess.    The Amel hull is so different that perhaps none of this will translate over but it would be nice to know for planning purposes.  Perhaps when I get my boat back to Florida waters I can attempt some testing but perhaps some other Amel owners have already done some experimentation?  

  I completely agree with you about trying to keep the heavy stuff as low as possible.  My heaviest items will also reside in the bilge.  

Best,

James
SV Sueno,  Maramu #220





Re: [Amel Yacht Owners] Amel Santorin Propeller Question

Alexandre Uster von Baar
 

Good morning Lisa,
Have you dive to see how clean was your hull and propeller?
If not, is your boat may be more loaded than before?

Sincerely, Alexandre



--------------------------------------------

On Sat, 12/16/17, lisallt2@yahoo.com [amelyachtowners] <amelyachtowners@yahoogroups.com> wrote:

Subject: [Amel Yacht Owners] Amel Santorin Propeller Question
To: amelyachtowners@yahoogroups.com
Date: Saturday, December 16, 2017, 8:43 AM


 









I own a 1997 Amel Santorin with what I
believe is the original propeller, which
is a 3 blade bronze propeller.  As you may know, there is
no manual in existence for the Santorin, and the boat
definitely does not have a feathering prop, as indicated in
the Super Maramu 2000 manual.  Is anyone familiar with the
type of prop that the Santorins were originally fitted with?
 The currently problem is that we are losing boat speed,
but with no change in RPM or engine sound. Everything else
appears normal.  Does
anyone know whether these propellers are bonded? We are
wondering if the loss
of boat speed could be a problem with the bonding on the
propeller bearing? 
Thanks
in advance for any ideas.  I also have reached out to Amel
Caraibes (we are currently in Antigua).
Lisa
TharpeS/V
Azimuth #143


Re: Amel Santorin Propeller Question

Craig Briggs
 

Hi Lisa - that's the same prop my SN came with, and I'm quite sure that's what was originally installed. 

The prop itself is not bonded and there is no bearing inside the prop, so that's not the problem. The prop is solid bronze with a tapered hole and keyway and simply slides onto the prop shaft. It's held on with a bronze "cone" nut and has no zinc.

I assume you've assured that the bottom is clean and that the prop is clean, so that likely is not the problem. However, given its age, the prop has certainly experienced some dezincification and is, without a doubt, slowly deteriorating. A thorough inspection may show a problem, especially on the leading edges of the blades.

After the prop and bottom, that leaves the power loss as an engine issue. Here's a link to a good article. https://www.sbmar.com/articles/understanding-low-power-troubleshooting/

Basically, they suggest if you have dark or black smoke throughout the rpm range of normal operation, you do not have a fuel restriction problem. You may have an air restriction problem or be over propped. You are not over propped with that factory installed prop (if no dezincification distortions), so check your air intake (also not likely the problem on the SN).  If you do not have dark smoke that points to a fuel restriction problem like clogged fuel filter, water separator, pickup, etc, 

When you say you are losing boat speed, do you mean the boat won't go a fast as it used to at the same rpm, or does it lose speed as you are going along?  What engine do you have? Is the tach, by any chance, out of calibration?

Good sleuthing, Craig Briggs SN$68


---In amelyachtowners@..., <lisallt2@...> wrote :

I own a 1997 Amel Santorin with what I believe is the original propeller, which is a 3 blade bronze propeller.  As you may know, there is no manual in existence for the Santorin, and the boat definitely does not have a feathering prop, as indicated in the Super Maramu 2000 manual.  Is anyone familiar with the type of prop that the Santorins were originally fitted with?  The currently problem is that we are losing boat speed, but with no change in RPM or engine sound. Everything else appears normal.  Does anyone know whether these propellers are bonded? We are wondering if the loss of boat speed could be a problem with the bonding on the propeller bearing? 


Thanks in advance for any ideas.  I also have reached out to Amel Caraibes (we are currently in Antigua).


Lisa Tharpe

S/V Azimuth #143

 


Weight distributuion

greatketch@...
 

Danny,

I haven't done the experiment of moving heavy things from the middle of the boat out to the ends as a sailing experiment, and not sure that will every bubble up to the top of my priority list. I will be happy to speculate on the results...

I was taught that weight in the ends of the boat was always a bad thing.  That does not mean that this statement is true, but here is my thinking.  Assuming the trim of the boat stays the same, moving the weight out to the ends, as you said, increases the pitch moment of inertia.  That has a number of effects, and to my mind the most important one is it reduces the boat's natural pitch frequency.  She'll "hobbyhorse" slower--not less--just at a different frequency.

For most boats that would be a bad thing, because a "good" boat will have a pitch frequency high enough that it rarely gets triggered by waves, unless they are very short and steep.  Reducing the pitch frequency brings it into the range where it is closer to "normal" waves.  Also, with more mass, the oscillations will take more energy to stop, i.e. they will last longer. It is really amazing how quickly a boat can come to nearly a full stop when she is pitching at her natural frequency, all the energy that should be moving the boat forward, get used to just pitch her up and down.   

If we are changing the fore-and-aft trim of the boat at the same time it could get a lot more complex.

But, ultimately the dynamics we are talking about here are so complex and have so many moving parts the answer isn't easy to guess.

The only experiment I ever did that was even remotely similar was re-rigging a boat from stainless wire to dyneema--fairly dramatically reducing the roll moment of inertia.  What a difference! With reduced heel she carried full sail in 5 knots more wind, leeway was less, it just made her a better sailing boat.  And this wasn't a race boat, but a 40 foot cruising ketch.  I didn't notice a change in the roll frequency, but I didn't try to measure it either.

Bill Kinney
SM160, Harmonie
Fort Lauderdale, FL.


---In amelyachtowners@..., <lokiyawl2@...> wrote :

Danny,

   This is an interesting area of discussion that can affect the way that we use our boats.  I understand the simplistic explanation that you provided but I think that there is quite a bit more going on and suspect that the actual data from testing might seem a little confusing when those tests are done in waves of  varying period and amplitude.  

   I know that on an older traditional design such as Olin’s Dorade that spreading out the weight can work out well.  Dorade was in fact so comfortable (and fast, the restored Dorade is in fact still doing very well racing)  that trips across the Atlantic were chosen intentionally to have the wind forward of the beam because of this fact..and because the boat rolled downwind terribly. (grin)   I think that the reason spreading the weight worked for that type of boat (under most conditions) is because the bow was very fine with little buoyancy as compared to more modern wider boats and with the pitch heavily dampened by both a heavy mast and heavy ends that the bow did not lift enough to initiate hobby horsing.  This makes for a very wet boat of course and I suspect that if the wave period happened to be close to the natural pitching moment of the boat that the weight spreading was probably not a good thing, but this is just a guess.    The Amel hull is so different that perhaps none of this will translate over but it would be nice to know for planning purposes.  Perhaps when I get my boat back to Florida waters I can attempt some testing but perhaps some other Amel owners have already done some experimentation?  

  I completely agree with you about trying to keep the heavy stuff as low as possible.  My heaviest items will also reside in the bilge.  

Best,

James
SV Sueno,  Maramu #220



Amel Santorin Propeller Question

Azimuth
 

I own a 1997 Amel Santorin with what I believe is the original propeller, which is a 3 blade bronze propeller.  As you may know, there is no manual in existence for the Santorin, and the boat definitely does not have a feathering prop, as indicated in the Super Maramu 2000 manual.  Is anyone familiar with the type of prop that the Santorins were originally fitted with?  The currently problem is that we are losing boat speed, but with no change in RPM or engine sound. Everything else appears normal.  Does anyone know whether these propellers are bonded? We are wondering if the loss of boat speed could be a problem with the bonding on the propeller bearing? 


Thanks in advance for any ideas.  I also have reached out to Amel Caraibes (we are currently in Antigua).


Lisa Tharpe

S/V Azimuth #143