Re: [Amel Yacht Owners] Speed vs. RPM
John McDougall <j.c.mcdougall@...>
Hi Claude & others
My SM2000 no 330 had the Yanmar/Autoprop combination and max revs
would frequently drop to about 1700. This was always cured by
cleaning the prop. My berth is in Antibes and the rate of marine
growth seems very high there for a reason we needn't go into but
let's say the harbour fish are large and fat. Quite expensive as I
don't dive (and certainly wouldn't in the marina!). The prop was
subject to a recall by Bruntons and in May 2004 I had Amel fit the
spare fixed blade prop. This prop is still fitted.
It is difficult to compare the performance of the fixed prop against
the Autoprop but I would say the difference is so slight as to be
unoticeable without making a test under identical conditions. I
agree that the Autoprop is extremely sensitive to fouling and I have
specified a fixed blade prop on my "54" to be delivered at the end
of this month.
Finally, before the fixed prop was fitted I had it treated with
PROPSPEED a silcone based propellor antifouling which works by means
of producing a slippery surface that marine gowth cannot adhere to.
The result was fantastic - the prop was still clean a year later as
opposed needing to be cleaned every couple of months in summer.
Propspeed is very expensive but I believe Seajet Pellerclean to be a
similar product and this has just been rated as the best in March
Yachting Monthly and Motor Boat
magazines. Has anyone tried it?
-- In email@example.com, Claude Roessiger