On Wed, 28 Sep 2005 08:59:10 -0400, Larry wrote:

Stephen Trapani wrote in
:

But what's the deal? What kind of a system is it that they would design
it that way? Why isn't this system crapping out engines all over the
country?


Because our yard DIDN'T put a loop and anti-siphon break in that line.
There's no place to conveniently put it in our engine room above the
dripless. I don't know what they were thinking about after all those years
of installing this stuff. You can bet they heard all about it when my
captain got back here...(c;

When my Onan water-lift muffler failed I had a very similar problem
that (due to my ignorance about the physics of the thing) caused me to
lose a season replacing an Atomic 4 I assumed had a cracked block
(mechanic agreed, too!).

When I found water-fouled oil in the "new" (freshly rebuilt) Atomic 4,
I "clewed in". Finally.

Applying the sabre saw and a smaller friend in the locker, we cut out
the Onan, which looked like a stock pot and sounded like it was full
of rusty playing cards, out and put in a Vetus water lock in at about
one-third the size. I put in all-new exhaust hose and put a higher
loop in the exhaust hose just before it left the boat in the transom.

I have a Vetus siphon break device I could install as the final piece
of the puzzle, but as the manifold exhaust is *exactly* at the
waterline, and I am fastidious about turning off the raw water
intakes, I am not sure this is necessary, as getting the recommended
16 inches of vertical loop might mean the thing might be better used
in the head (it's appropriate for both applications).

Now I have a perfectly fine rebuilt A4 in my garage with 40 hours on
it. Crazy, eh?

R.