[C320-list] Exhaust elbow

[Jeff Hare]

What I think people have experienced is pinholes that can be hard or impossible to detect until they really start leaking. 

Here's one scenario that isn't hard to imagine.   When it goes, you'll be on your way to some destination or nice daysail somewhere.  Maybe its a long trip you planned for a while.  It'll probably start to fill the bilge and float the floorboards before you notice. You won't notice the bilge pump  because the engine will be running. You'll be alarmed thinking a thru-hull  is leaking or broke.   Etc....     Unnecessary stress in my opinion.  

In the end, you'd be happier to be able to replace questionable parts on *your* schedule rather than on "the  emergency plan".  :)

Boats aren't great platforms to try to squeeze every last drop of life out of each part (in my opinion).   I love it when I get through an entire 2 week cruise and nothing breaks. 

I'd say replace it.  And just cross that part off your list of concerns for many years.   I'll be doing that next year and our 2001 Yanmar has less than 275 hours on it.  

-Jeff 

------Original Message------
From: Dave Anderer
Sender: c320-list-bounces at lists.catalina320.com
To: c320-list
ReplyTo: C320-List at Catalina320.com
Subject: [C320-list] Exhaust elbow
Sent: Nov 28, 2009 3:28 PM

With the boat out of the water it is time to start the winter-list.  Only 4
months to get it all done.

When we bought the boat 4 years ago it had about 375 hours on the Yanmar.
 The surveyor was quite concerned about the corrosion on the exhaust elbow.
 He wouldn't commit as to how long it would last before total failure.
 Wouldn't even comment on if it would last the 6 hours to get the boat back
to our dock.  I bought some muffler repair tape and crossed my fingers.  We
made it, I pulled the elbow, and buffed the corrosion off in about 30
seconds.  Just light surface corrosion.

(This surveyor took the same approach on several other issues - they sky was
falling, but he wouldn't venture a guess as to when it would hit us.  As
I've pulled things apart I've concluded his concerns were pretty much all
unwarranted.  Waste of money.)

I put the elbow back in.  We've now put another 440 hours on it - TT is just
over 800 hours.  I pulled the elbow today.  Same surface corrosion (though a
couple spots bother me).  No evident carbon restriction in the manifold or
the elbow.  We run consistently at 2800 RPM and have observed no problems
with the engine.

Don't know if I'll bother replacing the elbow now or not.

Pictures of the process are at
http://www.catalina320.com/mediagallery/album.php?aid=236&page=1