Found my water leak....mercruiser 4.3

1216bandit

Petty Officer 1st Class
Joined
Aug 18, 2008
Messages
214
Last time out the bildge pump came on a few times. When we got back to the dock I lifted the dog house cover and could hear a trickle but the light was fading so I really couldnt do anything till today. I removed the dog house, left the boat tied down to trailer and backed it into the water. Darn exhaust Y pipe had a hole on the top surface and water was squirting up into the air like from a squirt gun. I am thinking it is a casting imperfection??? I cleaned the area up and used a JB Weld epoxy to seal it up. I just want to make sure this is an OK fix for this. There are no hairline cracks leading to this, just this one spot. This pic would be on the port side looking down onto the y pipe before the repair


IMGP6080.jpg
 

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
Re: Found my water leak....mercruiser 4.3

No casting imperfection... It's most likely what's left of an exhaust shutter... The old style shutters were on a SS shaft. The shaft would eventually wear through and the shutter would fall... Most of them ended up in the drive somewhere, or out the prop never to be seen again... But a few fortunate souls, like you and me, have them lodge in the bend of the Y-pipe, where they rattle and wriggle until they wear a hole in the pipe, and your boat starts filling with water.... Mine did it when I was 30 nautical miles out to sea :eek:... Don't you think that was an 'interesting' trip back!!!

Chris....
 

1216bandit

Petty Officer 1st Class
Joined
Aug 18, 2008
Messages
214
Re: Found my water leak....mercruiser 4.3

Sounds like you had a rather large leak Chris!!
So, is that epoxy fix acceptable?? Do I need to remove the Y pipe or anything else, and check for other pieces of the shutters? Really not looking forward to anything like your "interesting trip back"!
Thanx...Dan
 

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
Re: Found my water leak....mercruiser 4.3

The only way to do the job properly and thoroughly is to pull the engine. The y-pipe needs to come off, and NO, I wouldn't poxy it up... That area is below the water line, the poxy will come off and you'll start filling up again... Besides, you need to get all the old bits of shutter out too.... The new shutters are the new style. They just fit onto the top of the Y-pipe (and don't break like the old ones)... And the hole at the bottom? If you can find a GOOD ali welder, let him do it.... Otherwise, it's a new Y-pipe, and they don't come cheap....

Chris......
 

1216bandit

Petty Officer 1st Class
Joined
Aug 18, 2008
Messages
214
Re: Found my water leak....mercruiser 4.3

Can the Y pipe be checked for broken shutter pieces by removing the down pipe (not sure of proper name) between the exhaust manifold and the y pipe? My doghouse can be removed easily and I have good access to that area.
How about going from outside the boat...remove the outdrive to get the pieces out?

The hole in my Y pipe is not that big so if the epoxy failed it would not be catastrophic. Should that happen I have friends in the tool & die/ mold making business that have some pretty high tech ways of aluminum repair.

I really need to avoid pulling the motor at this time...so any ideas on how to get those pieces out would be great!
Thanx.....Dan
 

HT32BSX115

Supreme Mariner
Joined
Dec 8, 2005
Messages
10,083
Re: Found my water leak....mercruiser 4.3

Howdy,

If it were mine I would probably use my GTAW (TIG) welder and weld it if the aluminum alloy it's made out of is weldable.

After looking on EBAY, I found several of them for sale. So you can easily buy one new or used.

I don't think I would just epoxy it.....plus you don't really know if it's "paper-thin" in other places.....and getting ready to leak there too..... I would want to inspect it carefully before I trusted JB Weld, DEVCON, or any other epoxy.....

In either case, you MUST remove the drive and engine to get the y-pipe out of there. No other way to do it.

You can probably remove the broken exhaust shutter pieces by fishing them out with any "cable-grabber" etc. or you might be able to get in there by removing the drive and going in from the back.
 
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