tracking down a leak through the transom

[Trevthefox]

Hello everyone,

Was out on the water and noticed some water in the bilge. Had previously thought it was coming through a thru-hull fitting but I tracked it down near the y-pipe. (Check out the video). I've been searching through videos and parts diagrams to see if I can locate the most likely cause of the issue. My best guess is a leak through the lower bellows. I had recently replaced the lower bellows and was pretty sure I did the replacement correctly. However this last outing makes me think I'm wrong.

Couple questions. My other guess would be through the y-pipe connection. However when looking at the parts diagrams I can't seem to figure out how everything is connected from the inside of the transom to the outside.

1) Is there a gasket or oring that connects sits in between the y pipe and the transom mount?
2) It looks like there is a ring (#71) that would act as the oring/gasket but what is #107? It says through transom exhaust plate, exhaust cover part #0125091 . It looks like that exhaust plate sits in between the y pipe and the connection for the transom mount. But that would block the water coming from the y pipe through the bellows to escape.

Once again I'm thinking/hoping the water is coming from a bad seal of the lower exhaust bellow. But if its not, it's most likely the y pipe but I can't seem to figure out how those parts all align.

See video to see the leak. (Sorry for the bad compression)
https://www.youtube.com/watch?v=hEnlwFDba6A


Let me know if you need more info to answer my questions. I greatly appreciate anyone who helps me out. I attached some pictures to help explain my nonsense.

Vessel is an 89 Bayliner Ciera 2855 powered by an 89 7.5L OMC 460 King Cobra

 

[kenny nunez]

It appears that your transom is in need of replacement. The exhaust bellows could be removed and would not cause a leak.
The engine and transom plate have to be removed and the wood and fiberglass material have to be cut out and replaced.

 

[kpg7121]

Yep, looks like a bad transom. One way to find out for sure is to drill some holes in the transom from the inside without going thru the outer skin. If the shavings are wet or water seeps out your transom is shot. They usually rot from the bottom up. What year boat, drive do you have?

 

[Trevthefox]

Yep, looks like a bad transom. One way to find out for sure is to drill some holes in the transom from the inside without going thru the outer skin. If the shavings are wet or water seeps out your transom is shot. They usually rot from the bottom up. What year boat, drive do you have?

It's an 89 Bayliner 2855 Ciera Sunbridge with the 7.5L 460 King Cobra. I can reach in there and the water seems to be coming from just above the transom bearing plate (see pic).

 

[ab59]

Same place mine was leaking and after I had just put the new engine in . Had to pull the engine and replace the Transom. Mine is an Aluminum so aside from a little more work then I wanted , the transom was not that hard to replace. Plenty of information on replacing transoms on a fiberglass boat here but unless there is some special reason you want to keep the boat you may want to consider buying another boat with a solid transom. Up to you.
Guess you could try to tighten the transom plate up a little and see if that stops it . Drilling test holes to check for rot is something to be done carefully so read a few threads about doing it before you try it. If you try it.

 

[Trevthefox]

Same place mine was leaking and after I had just put the new engine in . Had to pull the engine and replace the Transom. Mine is an Aluminum so aside from a little more work then I wanted , the transom was not that hard to replace. Plenty of information on replacing transoms on a fiberglass boat here but unless there is some special reason you want to keep the boat you may want to consider buying another boat with a solid transom. Up to you.
Guess you could try to tighten the transom plate up a little and see if that stops it . Drilling test holes to check for rot is something to be done carefully so read a few threads about doing it before you try it. If you try it.

I'll give it a shot. Any way to remove transom plate and reseal without removing the engine?

 

[ab59]

Not in mine but you will just have to try and see. If you've got long skinny arms you might have a chance :lol: but really , you will just have to try and see.
A word to the wise, if your transom is badly rotted and you doctor it up to run it a little longer it could cause some real problems if it comes apart out on the water. If you think you have a leak now , just wait until the transom craters and the entire lake comes rushing in .
Taking the extra time now to do what you will have to do later anyway is a good idea and you won't have to worry about the problem any more. Just sayin.
A.B.

 

[ab59]

Ohhhh you said transom Plate . The engine will at least have to be moved forward enough to get to and remove the plate. In the end it would be most advantageous for you to just remove the engine to get to the plate and do your work. Access to do the job right is a lot better .
A.B.