*pressure* water into the raw water intake can indeed overfill the waterlift
muffler once the engine is not running, and it doesn't take long.

As far as "cleaning out" the cooling system by flushing after use, that just
doesn't play. The cooling system gets clogged up by a.) "carbonates" loosely
meaning the various salts that plate out on the cooling system walls as hot
salt water (which has LOTs minerals in it), and b.) crud -- like silt -- that
falls out of the water as it flows through the cooling system.

And Yanmar raw water cooled engines were more suseptable to both a.) and b.)
than other raw water cooled engines of the era.

And again, do NOT turn pressure water on when the engine is not running.
Better is to run the water into a 5-gallon bucket and suck it from the bucket
into the engine.

your explanation was not clear that the engine MUST be running.

On 27 Jan 2004 15:22:20 GMT, (JAXAshby) wrote:

larry, do that as you suggest on a Yanmar with a waterlift muffler and you
will
cause some expensive to repair damage.

How? The engine is RUNNING during the flush. Feeding fresh water
into the stream into the RUNNING water pump simply replaces salt with
fresh. Any fresh water not pumped into the engine by the engine's OWN
water pump (whos impeller, by the way, meters how much water it passes
because my way has no hose pressure on it to speak of)...any excess
fresh water is simply fed backwards through the seawater strainer,
probably clearing it of the crap and run overboard unless the intake
or strainer is clogged, of course.

As the engine is RUNNING, there is no waterbox flooding or exhaust
backup because of the exhaust pressure of the engine. No excessive
water pressure is applied to the engine, any more than the water the
seawater pump on the engine imparts on it.

How's it going to destroy the engine this way. Simply turn off the
hose as soon as you stop the engine......before the seawater is pumped
through it, again.

You'd probably NEVER have to flush or core the cooling system if you
did it every time you used it.....even on closed systems with a heat
exchanger!


Larry W4CSC

Is it just me or did the US and UK just capture 1/3
of the world's sweetest oil supply? What idiot wants to
GIVE IT BACK?!!