water leak

[Cptkid570]

Hi everyone,

I tested out my new to me with reman engine boat this weekend. 1985 26? searay. 260hp mercruiser with Alpha 1, raw water cooled.

There is a small water leak in the rear where the exhaust exits the boat. I?ll describe it best as a ?strong trickle? when the engine out of the water running on the hose.. and is stronger when the boat is in the water. It?s nothing that the bilge pump can?t handle (so it?s not extreme), but I want to fix it before I go out again.

Here are the tests that I?ve done?
1. when running on the hose or in the water, the water is coming in
2. when on the trailer, I took of the riser and stuck a hose down the Y-tube and water was still trickling in. I can?t see down there very well, but it appears to be coming out somewhere around where the Y-tube mounts to the drive housing
3. While the boat is in the water, with the engine off, the water still comes in, so it?s not just the water coming out with the exhaust

I?m suspecting 1 of 2 places for the water to be coming in. Either one of the bellows (driveshaft, exhaust, or shift cable).. Or where the Y-tube mounts to the drive housing. However, since it leaks with just sticking a hose down the Y-tube, I?m guessing it?s not one of the bellows.

If it?s leaking where the Y-tube mounts to the drive housing (on the inside of the boat), would water still be able to leak in?

What are your opinions of this? Is it common for a leak to happen down there?

I just put the engine in recently, so maybe I knocked something down there.. but, it?s no big deal to pull the engine again and take a good look at it, but if I can avoid pulling the engine, then I?d like to.

I tried to get a camera in there and take a couple of pictures, but it doesn?t really show too too much?I?ll post the pics anyway though. The pictures have an arrow showing the water, but the source of the water is up higher than the actual arrow.

Thank you for any thoughts on this?.

 

[Cptkid570]

Re: water leak

Here are the photos:

 

[Cptkid570]

Re: water leak

I'm still thinking about this problem... is there some sort of O-ring or gasket where the Y-Tube mounts to the outdrive housing? Does that have tendencies to leak?

Since water comes in when I just put the hose into the y-pipe, I'm wondering how many different places this could be...

 

[Haut Medoc]

Re: water leak

There is a gasket between the y pipe & the inner transom plate.....
I would not be a bit surprised if a 22 year old y pipe rotted out , esp. if it had been moored in salt water.....
I would pull the engine, it will only get worse....​

 

[Cptkid570]

Re: water leak

I'm with you Haut. I'm really hoping it's the gasket and not the Y-pipe. I'm also hoping the bolts are ok. I'm having visions of a bolt breaking off and then I'm really screwed..

 

[Fishermark]

Re: water leak

There is a rubber o ring type of gasket between the y pipe and the transom assembly. From your pictures, it almost looks like your transom is cracked. May just be an optical illusion. While the engine is out, I would certainly check the transom for "soundness" - be sure it is solid and not rotted out, otherwise you will be pulling everything back off again anyway - even if the imediate problem turns out to be the y pipe or gasket.

PS - You will need a 12 point socket to remove the bolts. It is a 3/8" 12 point that is needed if memory serves me corectly.