wrote in message
...
John H

On Sun, 7 Oct 2007 23:35:23 -0700, "Calif Bill"
wrote:


"John H." wrote in message
...
On Sat, 06 Oct 2007 20:35:42 -0700, Tim wrote:

On Oct 4, 10:22 am, Wayne.B wrote:
On Thu, 04 Oct 2007 08:17:57 -0400, HK
wrote:
To me, the real downside of an I/O is the drive and the drive's big
rubber boot. The drive, because it adds complexity, and the boot
because, well, use your imagination.

We have a lot of I/Os in our area of SW Florida, including about 80%
of my neighbors. Interestingly enough you don't hear about many boot
problems although one neighbor did succeed in ripping the I/O clean
off the transom creating a boot failure of sorts. :-)

Cooling issues, manifolds and risers are near the top of the list
based on what I've observed.


I was going to say,t hat if I had an I/O on salt, I'd want an enclosed
cooling system, but still pull the boat after every use, and flush the
lower end with fresh water.



I googled marine cooling and this is one of my responses:

http://tinyurl.com/cqhmu

Some good info on cooling systems he

http://tinyurl.com/yozrfc

I wish I'd known about the fresh water systems when I bought the boat.
I
don't know why they aren't the standard, although they may be the
standard
now. I wonder how much more difficult changing the oil filter becomes
with
all that extra piping and the exchanger mounted over the engine?

My heat exchanger is on top of the motor, just inside the port riser.
Changing the oil filter is no more problem than a raw water cooled motor.
Major reason that freshwater cooling is not standard, is it adds about
$1000
to the cost of the motor. The Exchanger itself is about $6-700.


Looking back now, I'd gladly pay the extra $1000 if the benefits are as
described. New manifolds and risers run about $6-700 also.

I sure someone will correct me if I'm wrong but, IIRC, the fresh water
cools only the engine. Salt water is still used to cool the fresh
water (in the heat exchanger). It is pumped in from the sea with the
standard water pump in the lower unit and returns to the sea by way of
the exhaust manifold(s), just like standard cooling. So if you're
thinking you'd be saving the manifolds from seawater's rust and
corrosion, you'd be wrong (if I'm right in my recollection).

Rick

You can have freshwater cooled or raw water cooled manifolds. Mine are
freshwater cooled. On the freshwater, there is a plate blocking off the
risers and the raw water cools them. So just the risers have to be
replaced. Mine are aluminum, and the last ones lasted 14 years.