Exaust Seal

[Shep111]

I have an 89 mercruiser, alpha 1. I had water coming in the boat & did an experiment to see where. Boats on the trailer, I plugged the exhaust port after removing the exhaust bellows & opened the exhaust at the riser. I ran some water in the exhaust tube & sure enough water almost instantly started leaking under the exhaust tube where the two come together & exit the transom. I have the engine ready to pull but don't want to leave it hanging to long waiting for parts. The guy I usually talk to at the marina near me says, if the boat had been run hot, which it had last year because of the impeller went bad. Then the seal on this exhaust tube, @ the transom probably also got damaged. Well, they don't stock this part and I haven't been able to find it online any where. Iam starting to wonder if it exists.
I don't really know exactly what it's called but also don't see it on any diagram. ??? Any idea's or help. Thanx in advance, Shep

 

[Bondo]

Re: Exaust Seal

Ayuh,.....

I can think of 2 possibilities,....

1 is the Flappers burnt up,+ it's leaking from there,...
Or,....
The O-ring/ Seal you're asking about.....
It's #12 in this drawing.....
Click Here...

 

[Shep111]

Re: Exaust Seal

Thanx Bondo...........The flapper you mentioned, is that also called the shutter & if so, how many of them are there? One in each tube or just one before the whole thing exits the transom?
Thanx again, Shep

 

[Bondo]

Re: Exaust Seal

Ayuh,....

An 89 should have 1 each side...

 

[Bt Doctur]

Re: Exaust Seal

The "Y" pipe could be corroded thru also.

 

[BAYLINER185]

Re: Exaust Seal

Yea the Y Pipe has an O ring that sits in a little channel. It looks like a round rubber gaskit thats "tubular", meaning the sealing surface is round. Its like the Trasnsom seal only much smaller and made of rubber. Mine went bad and it was that stupid little 20 dollar part that costs an arm and a leg to replace due to al the labor. Its cool that you can do that your self. I have a Cruser and no way to pull a 454 or have the room to do it if I did.

As mentioned above abotu being rotted through. I think that is always a possibility especially in salt water but I think it wold take a really long time to do so in fresh water. Being an 89 I think it may be unlikely. I had an 84 wellcraft with a 4 banger and all those exhaust parts were in perfect shape. Of course every boat is differant and once you pull it apart you will be able to tell the story.