[C320-list] Muffler leaks and drainage

[Troy Dunn]

Graeme

We discovered our muffler was leaking mid summer.  As others have mentioned
once this starts to happen you can mess around with temporary repairs but
it is unlikely your repair will last very long.  By the time we realized
what was really going on, the area under our engine was filling with enough
water after a day of sailing and motoring for maybe half an hour that the
water was overflowing that compartment and moving into the salon bilge.
Once that happens it's pretty easy to see that the muffler is your problem
as the failure point is the seam between the bottom panel and the top box.
  This seam faces down actually so what you should notice is a vibrating
pool of water around the muffler that spills off the mounting deck and
beneath the shaft.   Figuring out exactly where the leak is coming from is
more challenging.  To do this you need to remove the muffler from the boat
and seal it up.   I used sandwich bags and rubber bands.   Use a compressor
to add a very small amount of pressure.  I just poked a hole in one Baggie
with the nozzle.   Use soapy water as a leak detector.   In our case two
seam edges had failed.   I used my dremel tool with cutting wheel to cut a
slot at the seam down both edges and used JB Weld.   I also drilled out the
bolt holes and reinforced them with small copper bushings per the article
on the web site using epoxy as an added measure...in for a penny and all...

This repair got us through the season, but by late October the muffler was
leaking again.   I shipped it to CD in November.

One interesting anecdote.   Our muffler leak actually revealed a small fuel
leak in the lifter pump.  We noticed a very small sheen under the engine.
We got a cheap set of offset screwdrivers and tightened the screws around
the pump and that fixed that leak....and we no longer noticed the 'exhaust
smell'.   You may want to see if you have a similar problem.

Also, If you don't have water in your bilge then your muffler isn't
leaking.

Troy Dunn
Hull#514