Not uncommon. Not sure of the reason. I had 2 pontoon boats that both lost
4 mph on top end thru the first year (boats were not left in the water and
pontoons were clean). Also, my 24' cabin cruiser lost about 300 rpms on the
350 Mercruiser thru the first year on the new engine (again, boat was
trailered and never left in the water and hull was clean). This was a used
boat so the hull should have already absorbed what water it was going to.

If anyone has an answer - I would love to hear it.
Only my speed boats have not seen this happen.


--
Tony
my boats at http://t.thomas.home.mchsi.com

"Peter Jones" wrote in message
om...
Started the new season to find my Conquest 23 with Merc 4.2 D-tronic
diesel on a Bravo III seemed to have "lost" 300-400 rpm at WOT. After
many visits by mechanic and Merc distributor with laptops, replacing
fuel injection electronics, rigging up a clean fuel tank etc - the
conclusion was "the boat got heavier" and they propped it down from
24" to 20" to get it back to 3800 rpm.

Well, the only thing added to the boat since I bought it from new is a
fold-away table and some fishing rods and she's cleaned top and bottom
every winter - so I'm pretty skeptical!! I don't think a new whaler is
likely to be soaking up water in her hull either.

She's very lightly used but serviced every year. No smoke and sounds
sweet to my ears - even the wife likes the whining of the turbo!

Anyone got experience of this engine? Thoughts?

Thanks
Peter