Re: [Amel] Re: Volvo Penta TMD22 Low RPM


Hello Danny and the propeller problems with fouling and wear and RPM reductions are not exclusive to the Volvo engine installation (and the Perkins Prima which is virtually the same engine). I had a Volvo equipped boat as my first demonstration boat, and then two Yanmar boats that I purchased in succession for use as demonstrators. The Yanmar boats did exactly the same thing with even one gooseneck barnacle on the Autoprop. That, and the fact that I have sold at least 70 used SM 53’s over the years and prepared for every sea trial with a prop inspection and/or cleaning to make sure that proper performance could be demonstrated. The Autoprop is a fine device if it is clean but they have a real Jekell-Hyde character change when dirty.

Your comments on usage and carbon and so forth are right on the money. I have sold boats with 700 hours on the diesel where the motor was never run past about 60% of maximum output. Of course these were smoky and well down on power to the 7000 hour example that was run flat stick frequently and always attempted to be kept in the 75%-90% power range and with otherwise exemplary maintenance. Diesels like to work and protest if they are made to loaf…

I always smile when I see that you are out and about enjoying your Amel the way God and Henri intended. You are a fortunate guy!

All the best,


Joel F. Potter - Cruising Yacht Specialist, LLC

Amel's Sole Associate for the Americas

Mailing Address: 401 East Las Olas Boulevard #130-126

Fort Lauderdale, Florida 33301

Phone: (954) 462-5869 Cell: (954) 812-2485

Email: jfpottercys@...

From: amelyachtowners@... [mailto:amelyachtowners@...] On Behalf Of Danny and Yvonne SIMMS
Sent: Wednesday, June 26, 2013 7:16 AM
To: amelyachtowners@...
Subject: Re: [Amel] Re: Volvo Penta TMD22 Low RPM

Hi All,
It is of note that the problem is exclusive to the TMD 22. If it is a prop problem it beggars belief that no Yanmar equipped boats have trouble with their props. Surely all Yanmar owners do not do a so much better job of keeping any fouling off their propellers?

Also, as I understand the auto prop it automatically adjusts pitch to match power, and torque applied, the load, and boat speed. So the pitch would be different in a fully laden boat with all cruising gear on board, and 600l diesel and 1000 l of water and six persons and luggage aboard, pushing into 20 knots of wind and a chop, compared to an empty boat in flat water with no opposing wind. I would expect the fully laden boat to operate with a lesser pitch to allow revs to be attained, like changing down gears in a car going up a steep hill.

Likewise, if two identical boats, identically laden in identical circumstances, had different diameter propellers, would not the auto prop automatically compensate for this by applying a lesser pitch to the larger prop? It would do this on the boats with the 100hp engines running at less than full power would they not?.

I believe we may find different owners (or past owners) habitual usage of their motors over long periods may well be a factor. Diesel engines like to work, and work for long periods of time, to get good and hot and burn off accumulated carbon deposits.

Speaking of Carbon deposits. There is a cast iron casting at the end of the exhaust manifold. This is where the cooling water enters the exhaust system. It is a common problem across all engine types for large amounts of carbon the build up here, to the extent it can completely clog the exhaust. It is caused by the change in temperature as the water meets the VERY HOT exhaust gases. Twice recently I have heard of engines actually being stopped by this, one was a Kubota diving a gen set on an Amel, the other was a small Yanmar in a 30 footer. The owner of the Yanmar, a quite skilled home mechanic, had gone to the extent of removing the motor and completely disasembling it before he found the inaccessible exhaust almost completely clogged where the water and hot gasses met.
Food for thought,
SM 299 Ocean Pearl
Currently Cruising Fiji

From: Miles Bidwell <mbidwell@...>
To: amelyachtowners@... <>
Sent: Monday, 24 June 2013 8:35 AM
Subject: [Amel] Re: Volvo Penta TMD22 Low RPM

I have recently been having the same problem with my TMD22. I cannot get
more than about 1700 rpms, but if I stop and then flat stick the throttle,
the autoprop will spin up into the turbo range and then I have (what seems
to be) almost normal power until I let the rpms drop below 2100. The
maximum revs are 2700 instead of the normal 2800 as of last summer; however
the big problem is new this year. Over the winter, I had the fresh water
pump replaced and the injectors checked and adjusted and the turbo replaced.
The autoprop is clean and to make sure, the autoprop people just rebuilt it.
A fixed prop does not solve the issue. I am about to turn to the high
pressure fuel pump. Any suggestions will be most welcome.

Miles, S/Y Ladybug (SM 216) in Newport, RI

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