I am not 100% sure of this but fairly sure that the Autoprop was not a Amel
Yard installed option on the hull number you mention. The first thing to do
is make certain you have the right size Autoprop.
The main an usual cause of the rpm problems you have are due to fouling or
foreign objects, like monofilament fishing line, getting caught in the prop.
It cannot be overemphasized that the propeller needs to be absolutely 100%
clean with no growth or even slime on the prop. Even too much or unevenly
applied prop antifouling coatings will cause the problems you have. The prop
gets its "auto" function from the vortices coming off the very unusually
shaped tips of this propeller interacting with the blade behind it and so
on. Even one tiny gooseneck barnacle or any fouling of any description,
even stuff that can be felt but not seen, will cause the Autoprop to not
allow full rpm. Most folks hear this and roll their eyes and say, "yeah,
right..". Don't. It is really that critical.
The other source of trouble is that Autoprop had a general recall several
years ago where they replaced the bearings and their races with improved
units. If this was not done, or if you have more than 2000 hour on the prop,
it might need to be rebuilt.
Check the clean part first, then go from there.
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
[mailto:amelyachtowners@...] On Behalf Of islandbwoy4434
Sent: Monday, June 17, 2013 8:39 PM
Subject: [Amel] Volvo Penta TMD22 Low RPM
Just installed a reconditioned Turbo charger on Libby's (#196) TMD22. The
Turbo was indeed seized solid as was the waste gate actuator.
Prior to installing the re-conditioned unit we noted that the highest RPM we
could achieve was 2000. This gave us a boat speed of aprox 6-7 knots
depending on conditions. We have the factory feathering Auto prop installed.
Having read the associated threads on this forum I fully expected post
installation of the refurbished unit to achieve upwards of 2800 RPM and an
increase in top end boat speed.
Alas, not the case.
From a standing start the engine will rev up to 2300 RPM until the
feathering prop builds it maximum thrust and the RPM's drop down the 2000
RPM and 6-7 knots of speed.
I would like to know if I am missing something here with respect to my
Can anyone offer up some wisdom?
SV Libby #196