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leak at transom possible y tube bottom 1987 260

K

Kevin Conley

New member
Ok, so I just got a great deal on an '87 Searay Sundancer 25' w/ Merc 260, 3 days in the water and it starts leaking at transom. Guess that's why it was a deal. OK, so I pull it out, replace all bellows, water hose,shift cable, and install new trim sender & switch. Also new water pump in drive. Put it back in, and it's still leaking. What I thought was a leak from shift cable area coming down was really bubbling up from exaust y tube on starboard side. Am I going to have to pull the drive, and then pull the engine to attempt resealing the y pipe to the transom plate? I think I know the answer, but am hoping for a shortcut.
Thanks, Kev
 
Re: leak at transom possible y tube bottom

Can you see the leak exactly? Is it coming from where the Y-pipe attaches to the transom, or is there a hole or crack somewhere?

The older flapper/shutter style sometimes would come loose and drop down into the bottom of the Y-pipe. Then, after vibrating for awhile, they could wear a hole in the pipe, causing the leak. If this is the case, you will need to pull the engine (and drive) to get the Y-pipe all the way out, fix the leak and reinstall. You will need to align the engine and gimbal bearing when you put it back in.

But, it could be that one or more of the four bolts that hold the Y-pipe to the transom could be loose? You might potentially reach down there (it's a pain, and sometimes not reachable!!!) and see if they are loose. I think it takes a 12 point 3/8 socket? This would be the easiest fix. Otherwise you will probably need to pull the Y-pipe out and inspect.
 
Re: leak at transom possible y tube bottom

I can't see exactly where it's comming in, it's defenatly farther down towards the bottom. The flappers were stuck at the shift shaft when I took the drive off. I don't think they wore a hole though, I would think if that were the case the leak would be in the top part of the pipe. It seems to be in the area of the smaller bottom exaust port (stbd.). I was able to scrape off a lot of crud, and flush it out with a small hose. When I did that, there was water comming out of the small stbd. side exhaust port. I was thinking about just filling the entire area with epoxy putty for now to get the rest of this season, and pulling the whole thing apart over the winter. I'll try to see if I can get a wrench in there, but it's not likely. I was looking on e--bay at a couple of used y pipes, and it looks like the bottom bolts are prone to corrosion, Do they usually leak at the bolts, or at the gasket?
 
Re: leak at transom possible y tube bottom

I had a water leak on my 1994 mercruiser V-8. After running at cruise for 30 minutes there would be a few gallons in the bilge. Issue did not show up when running on muffs on the trailer. Laid down with a flashlight and mirror while my buddy drove the boat, could not see anything. Someone on this board said it was probably the y-pipe o-ring seal. They were right. Pull the drive, pull the engine, remove the y-pipe with a 12 point socket. 7/16" I believe, might be 3/8" or 1/2" (it's been 3 years). I replaced the o-ring and ran a small bead of gasket maker outside of the o-ring on the mating surface. So far so good.
 
Re: leak at transom possible y tube bottom

Well, I bit the bullet and pulled drive & engine last night. Boat doctor is right, the bottom of the y pipe was eaten away, not just on one side where the leak was evident, but both sides were pretty well eaten away. Now I'm glad I didn't try to shortcut it and fill with epoxy putty, it probably wouldn't have worked anyway. If I had let it go much longer, it probably would have started eating away the transom plate where it mates to. Thanks for the input guys, I kind of knew what I needed to do from the start, (but didn't want to admit it). I needed a sounding board to talk me into doing it right the first time. I guess I could have saved some bux by going to the heart of the matter before installing all new bellows & shift cable, at least I won't have to worry about those for a few years.
Thanks, Kev
 
Re: leak at transom possible y tube bottom

Listen the Doctur is always right, might not be what you wanted to hear, but the truth hurts sometimes.

You got a empty engine bay now? You could do some inspecting and checking every inch. Check them stringers when the engine mounts go.
 
Re: leak at transom possible y tube bottom

And while everything is out you might replace the water inlet tube in the transom plate - where the water comes from the drive to the engine. They have been known to "wear" from sand in the water, corrosion, etc.
Cheap and easy.
 
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