Aqualift leak at bottom

[Roc]

Seems like I found an exhaust leak, not where the hoses are attached, but coming from the bottom of the muffler, where it is bolted to the hull.  Used soap and water to check around all the hoses and no leaks were found.  When I felt around the base, I felt air coming out where it meets the hull.  No water, just air.  Has anyone ever found an exhaust leak in that area??  What's weird is that no water comes out.  Does this sound reasonable?  I plan to take it off and marine tex any cracks.  I will also install a hump hose.  Seems like a bolt on/bolt off project to take the muffler off. Any suggestions would be appreciated.  I did do a search and read stuff about the muffler, but most failures are at the hose connections.

Thanks,
Roc-

[Roc]

Thanks Ron, my plan was going to be just as you suggest.  I guess there isn't really that much water in the muffler, that's why I don't see any water leaking, just the feel of exhaust gasses from the bottom when I put my hand near it.

Regards,
Roc-

[Roc]

Ron,
My MkII muffler has the input/output hoses on the sides, not the top.  My guess it the leak is coming from the joint where the bottom is attached to the sides.  Can't tell until I take the muffler off.  My plan is to dremel out the crack and use West epoxy and some mat. Thanks for giving me the tip to sand the paint off down to the glass in the surrounding area.

Thanks,
Roc-

[Roc]

Well, I pulled the muffler out and took it home.  Plugged up the outlet hole and rigged the inlet hole to use my dinghy pump to put some pressurized air inside.  Submerged the muffler under water and pumped away.....no air bubbles, no leaks found.  Written on the bottom of the muffler with big black letters was 'Pressure tested to 5PSI' and the date it was done.  Looks like it was tested at the factory.  So it seems there is no leak from the muffler. I think the air I do feel coming from beneath it is the movement of the bottom of the muffler from the pulsating exhaust gasses.  The bottom seems like it's only about 1/8" thick, so I guess it does naturally move.  I re-installed the muffler with T-bar clamps, double clamped.  I still smell exhaust in the aft cabin and in the aft locker after running the engine for about an hour.

Any ideas of where to look are appreciated.

Thanks!!!!

[Stu Jackson]

Roc

Try looking at the connection of the exhaust riser to the back of the engine manifold.  That's the only other connection if you smell fumes.  Also check the nipple where the cooling water enters the riser.

[Mike Vaccaro]

Roc,

The crankcase breather is another possible source of fumes in the aft cabin area.  The stock set-up is a clear plastic tube attached to a 90 degree elbow fitting at the top of the forward end of your head cover.  This tube snakes along the block behind the alternator.  Some of use have plumbed a recirculation line back to the air intake to eliminate this odor.  A search or find of the messages will provide some ideas on how to accomplish this if you want to try.  As I recall, there is also a "how to" on the Catalina 36 website as well.  If you choose to plumb the breather this way, be sure to use some sort of filter in this line to prevent oil from recirculating back through the air intake.  

Good Luck,

Mike

[Tom Soko]

Roc,
Pictures of a re-routed crankcase breather hose can be found at:
http://www.imagestation.com/album/?id=4288188659&code=7709261&mode=invite
They are pictures #58 & 59.  Hope this helps.

[Ray & Sandy Erps]

Roc,

Did you find the source of the exhaust leak yet?  I went through the same thing last month.  Started looking at the water muffler, not there.  Grabbed a hold of the exhaust pipe and found that it was loose, that I could move it.  After removing the exhaust pipe, I found that it wasn't stock, that it had been fabricated out of stainless steel pipe and was in good shape except that a weld had failed.  It wasn't readily apparent because it was hidden by the insulating wrap.  Had it re-welded and bought the flexible hump-hose and re-installed it.  I hope I'm good for another ten years at least.