Black Bilge water

[Analgesic]

This Summer we used our engine much harder than usual due to a long cruise with little wind.  On the last day I discovered a fine jet leak from the lower right ?bolt of the water lift muffler under the head sink.  It looked corroded, I did an emergency epoxy glue patch and finished the trip.  The next time I checked the bilge the formerly clear water had heavy black particulate matter, a dramatic change I never saw before.  There was no obvious new odor and no floating oil.  Shortly after, on my last motor to haul the boat, I thought the cabin smelled of diesel exhaust.  Anybody have advice regarding what is going on and what I have to do between now and May when I relaunch?  I know the easy answer is call a diesel guy, but I like to save $ when I can and learn by doing things myself when practical.   Thanks in advance.
Brian McPhillips

[tonywright]

It sounds alarming to me. Do you have a CO detector installed? It sounds as though you may have a crack somewhere in the exhaust. If any doubt at all, I would have it checked professionally. CO is odorless, and it kills.

Tony

[lazybone]

Sounds like you still have an exhaust leak.  "Black particulate matter" is exhaust soot, it tends to collect at the bottom of the lift muffler. A crack in the bottom of the muffler would allow it to flush out and into the bilge.  Replace the muffler and install a hump hose.

[Mike Vaccaro]

Brian,

Which bolt was leaking?  When you open the head door, there is a stop cock in the lower right corner (vertical face) of the muffler as well as a lag bolt that holds the muffler in place.  The lag bolt is on the outward turning flange and has a normal bolt head. 

The stop cock allows you to drain the muffler for maintenance.  They do tend to leak/corrode with time. 

If a new muffler is required, you'll need to remove the old one and return it to Catalina--they'll make you a new one in about a week.  You can do some searching and you'll find a couple of "how to's" on muffler, hump hose and exhaust riser replacement.  If the muffler has leaked from the base, the base may be rotten as well--this is a simple wooden platform that is tabbed into the hull. 

Best of Luck,

Mike 

[Stu Jackson]

Muffler drain -- Mike's right about purpose of the plug on the muffler.  I had to open mine last week when I had some hard starting (which was because the fuse holder and wire extension with a connector from the red tracer/yellow wire from the start button to the starter solenoid that I installed in 2004 needed to be redone - the fuse holders they make these days don't last 20 years like the old ones did!  ).  So, I always thought that the plug would drain through the middle, like most plugs do.  Wrong -- turns out that what's there is the head of a standard drain plug connected to what appears to be a big fiberglass threaded piece that actually screws into the muffler body.  It's not metal in there, so all the time over the years I've been spraying it occasionally with PB Blaster made no difference.  Try unscrewing it and see what I mean.

Ron Hill wrote a long piece about removing the muffler.  Try the Knowledgebase.

Would also be helpful if you gave us some more info about you and your boat (http://c34.org/bbs/index.php?topic=1506.0).

Thanks.

[Ron Hill]

Brian : I'll guess that your aqualift muffler has a seal break (internal fracture where the top and bottom come together) in the vicinity of that carroded lag bolt.
If you don't want to spring for a new muffler you can try to clean out the inside with lacquer tinner/acetone.  Then mix up some slow curring epoxy put it inside the muffler and tilt it so the epoxy flow toward that bolt hole.  After it cures run a low pressure test.

Many times the factory would make the muffler and drill the holes too close to the seam.  Guess that your "hard engine" stress/vibration broke that seal and you got a leak.  If you don't have a "single hump hose" on the inlet of the muffler - you need one (call Catalina parts) !! 

[Analgesic]

Thanks to everyone.  The leak seems to be from the lower right stop cock area but I didn't see anything functional, something must have corroded off or vibrated off.   This all happened over labor day weekend and I recall trying to tighten something with a ratchet wrench after I sealed the leak and I heard the dreaded crack of tightening one turn too many.  Sounds like the answer is to remove the muffler and inspect/repair/replace it.   
Brian

[Ron Hill]

Brian : Remove the muffler and see what the situation is on the drain cock.  Maybe you can get away with only a new drain cock from Catalina parts??   
If you decide to fix it, make sure that you conduct a low pressure test when you're finished so you know your fix works/is holding!   

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