Intro and request for info on engine leak

[Biggvs_Richardvs]

Hello,

My name is Rich and I'm up here in BC with an '89 SeaRay with an OMC Cobra 4.3 in it.

I have a leak.

It only leaks with the engine running, and I have traced the leak down to the little wide U-shaped are just below the Exhaust T and above the transom plate.

Has anyone else seen that before and can maybe suggest a likely cause? Both bellows look to be in pretty good shape. If it was the shifter cable, I wouldn't expect it to only happen with the engine running, plus I still get the leak out of water and with a hose hooked up.

Here's a quick 1 minute video of the leak:

https://youtu.be/TNht3Fq_SvU

Sorry the camera is sideways, but its a really tight space.

Any help/advice greatly appreciated

 

[tpenfield]

:welcome:

It appears that we are looking at the bottom of the "Y" pipe in the video. The engine probably has to come out in order to get good access to repair that. Being an OMC cobra, I'm not sure how plentiful the parts would be, but I do see some on eBay.

 

[Scott Danforth]

Pull motor to get to the y pipe

 

[Biggvs_Richardvs]

Thanks guys - I appreciate the bad news

Quick question - could I access that from the other side by pulling the drive, and would that be easier? I'm pretty new to OMC, so still getting a feel for what is practical/feasible.

We're thinking about just filling that wide U shaped area with spray foam to cut/slow the leak. I have 2 electric bilge pumps and 1 manual one, plus a kicker motor for trolling, so the plan is to get through fishing season as best we can and then pull everything apart sometime round november.

Thoughts?

 

[tpenfield]

No . . . Pulling the outdrive is necessary, but will not make it any easier.

 

[Bondo]

We're thinking about just filling that wide U shaped area with spray foam to cut/slow the leak. I have 2 electric bilge pumps and 1 manual one, plus a kicker motor for trolling, so the plan is to get through fishing season as best we can and then pull everything apart sometime round november.

Ayuh,..... Welcome Aboard,..... With a bandaid like that,... That's a boat I would Not want to be on, unless on the trailer,....

Until you absolutely pin-point the leak, it's a guessin' game,....
The big u-shaped thingy is known as the y-pipe,...
It's Full of water all the time the boat is in the water,.... it Should leak All the time,....
That y-pipe is the only thing 'tween floatin', 'n Sinkin',.... a 3" hole,....

I don't do OMCs, But,....
I'd sooner think the hose comin' from the drive, goin' to the t-stat housin' might be leakin', 'n just runnin' down to where ya see it in the vid,....
That hose moves water, Only with the motor runnin',... 'n there's a fittin' there,...

Water flows Downhill,....
From where ya see the water, look further Up, til it ain't wet anymore,..... ya just went past the leak,....

 

[Biggvs_Richardvs]

Ayuh,..... Welcome Aboard,..... With a bandaid like that,... That's a boat I would Not want to be on, unless on the trailer,....

Oh believe me, I know.

I've been going out with it just leaking for the last couple months, so anything's an improvement for me. The leak is slow enough that normally the bilge pump handles it fine, and when it (the bilge pump) quit the other day, I only had to hand pump it twice in about 8 hours of trolling, so it's pretty manageable. Obviously not ideal...

the problem is, our fishing season here is really short, and the Salmon have just started to come in. If I start in pulling the drive and engine now, I'll probably miss the Salmon season entirely, if for no other reason than lack of parts. The postal system here is extremely slow - it could take weeks if I discover I need some new gasket to get everything back together or something like that.

This is Vancouver island - have you seen that show "Alone?" Ya, it's like that. So I'll just deal. I have a marine tow service on standby, 2 bilge pumps, plus a manual one, etc etc etc. Good times, good times.

I really and sincerely appreciate all the good info though. When I finally do have the engine and leg off, besides fixing my leak, can anyone recommend the top things to replace/fix for preventative maintenance?

Also, if there's a good youtube vid of the removal and reinstall of an OMC engine/leg out there, please pass it on. I do have the factory service manual, so it's a start, but any additional help to get the procedure straight in my head would


Many thanks,
Rich

 

[Lou C]

Ok there are a few places that water can leak there, one is the hose that goes from the transom mount (inner) to the power steering cooler on the rear of the engine. This is a short hose that's hard to get at, they rarely fail but see if you can get in there and tighten up the clamps. The only other thing I can think of is the o ring seal between the bottom of the Y pipe and the inner transom mount exhaust housing. But as noted, you can't access this unless the engine is out of the way. If you have access to a hoist, it doesn't have to come all the way out, just forward about 2 feet so you can get in there. Drive comes off first. Hopefully its only the seal and the Y pipe is not corroded where it seals to the exhaust housing.

​Things to check while you have the engine out...
​starter
​oil pan for rust/leaks
​that bilge pump way back at the transom
​power steering cooler, hydraulic lines...
​take a good look at the splines on the engine coupler, if they are not nice and square and you see rubber dust on it, then replace that too. expensive but that's the time to do it.

​If you need a Y pipe I have seen them on Ebay. It is possible that a Volvo pipe from the joint venture Cobra/Cobra SX line might fit, but that's just a guess on my part....