Re: [Amel Yacht Owners] LOW ENGINE RPMS ON YANMAR 75


When I was told by Bruntons that my Autoprop was what they recommended for a SM with 100 HP Yanmar, I had my fixed prop (which a good prop shop said was also over pitched for my 78 HP Volvo) repitched to what was recommended and got good rpm  again.  The Autoprop couldn't be repitched, so I replaced it with a MaxProp...not so persnickety as the AutoProp.
I wish I'd serviced the Autoprop first, it might have saved me 1000's of $.

I still have the repitched fixed prop (which is now under pitched for my new 110 Yanmar), and the old Autoprop which still hasn't been rebuilt.
If any one would like to buy either of these (but not both) I'd be happy to sell it for about half price plus shipping.
SM 243
Karkauai at yahoo dot com

On Dec 6, 2015, at 5:20 PM, sailormon kimberlite@... [amelyachtowners] <amelyachtowners@...> wrote:



On kimberlite I had a loss of engine power. I tried everything and finally decided it was the prop. I ordered the stuff from AB marine and rented the tools. When I hauled the boat everything seemed fine . There was no play in the prop blades and everything spun freely---What the heck- I rebuilt the prop.

That was the problem. It is hard to believe that a few thousands of an inch makes a difference in the Autoprop performance, but it does.

Fair Winds


Kimberlite Amel Super Maramu #376



From: amelyachtowners@... [mailto:amelyachtowners@...]
Sent: Sunday, December 06, 2015 4:22 PM
To: amelyachtowners@...
Subject: Re: [Amel Yacht Owners] LOW ENGINE RPMS ON YANMAR 75




When I had loss of rpm with my Volvo, I had the Autoprop cleaned and even out of the water all the blades spun freely on the hub.  I know that the only thing I didn't do (because I didn't know better, was to have the prop serviced.  Others have said that solved their problem.  If its been awhile since it was serviced, I'd do that even if the blades spin freely.


SM 243


On Dec 6, 2015, at 5:54 AM, Ben Driver/YAHOO joedoakes66@... [amelyachtowners] <amelyachtowners@...> wrote:


Thanks.   I'm diving the boat today .. It seems most feel prop is most likely.  If not, I'll move through all suggested fixes 


Ben Driver 

SM 347

La Bella Vita

Ben Driver

On Dec 4, 2015, at 12:20 PM, Germain Jean-Pierre jgermain@... [amelyachtowners] <amelyachtowners@...> wrote:


Hello Ben,


I have a Volvo TDM 22 but diesels are diesels…


I encountered these symptoms on another boat… badly crusted propeller…


Other cause might be a faulty turbocharger.  Generally, we tend to baby our engines and this is not good.  I try to run at 80% or more power for 1 hour out of every 24 hrs of engine time.


Third possibility = a collapsed air filter.  BTDT.


Good luck.. at least the trouble shooting should be easy.



Jean-Pierre Germain,

SY Eleuthera, Amel Super Maramu 007

Porto Turistico Marina di Ragusa, Pontoon M15,

97100 Ragusa, Sicily, Italy
+44 7551 211 511



On 4 Dec 2015, at 17:09, joedoakes66@... [amelyachtowners] <amelyachtowners@...> wrote:




I bought my SM in Feb 2015  and there are still many systems I need to better understand.  Most perplexing is I have seen declining engine RPMs since original survey.  Originally boat produced about 3100 RPMs (Yanmar manual says 3600/3800 tops - but I do know Autoprop may limit that number)  but has since declined to 1800.  Not sure why as engine seems to run fine - easy start, no smoke, no roughness at any RPM.  Racor and engine filters are new.  Manual shut off valve in passageway  is wide open (it actually will not shut off motor... but that's another issue).   I do have an Autoprop which was serviced well over a year ago - but not sure - by previous owner. Only other engine oddity as it runs very cold - never over 130F.   Boat has been in the water now for a little over a year with not much motor use.  Any and all suggestions would be welcome. 


Ben Driver

SM #347

La Bella Vita


Posted by: joedoakes66@...

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