mercruiser 4.3 with alpha-one water coming in from behind engine

I, I pulled my boat out of the water last fall because water was coming in from behind the engine when resting... I could see the water jet coming upward from what look like u-joint attach to a driving shaft behind the engine. I had my 3 belows changed two years ago. Can it be something else then the belows ? I just remove the drive and if I look at the belows they look fine, I will continu removing parts until I can see something odd... Would somebody have any advice ??

What year is the engine and drive? Was there water in the bellows when you pulled the drive?

Being that you said "I could see the water jet coming upward from what look like u-joint attach to a driving shaft behind the engine" My guess would be the Y-exhaust pipe is rotted and leaking or you have a rot hole in the transom assembly.

THE BOAT IS A COBALT 1993, I was told that the drive had been changed... I could not be more specific but with thw serial #. Please note that my english is second language, so not perfect ! As for the water jet... it was coming from a piece of metal, not fiberglass. I could actually, with a lot of finger, twisting block it. I was just unable to see... And finally I just removed the drive last week end, and there could not possibly be any sign of water as the boat is in my heated garage (with wood stove)...

Heated garage or not, if there was water inside the place where the drive shaft and u-joints go, it would still be there. I think you have a rot hole in the transom assembly. You will need to pull the engine to inspect it. With the drive off it should take about an hour or less to get the engine out.

BTW what is your first language?

I'm a french men from montréal... I hope you meant to remove the drive... not the engine. I am an andy man with about every thing, but by no meen a mecanic. I watched some videos on youtube and thought I could get away with removing the drive. If I have to move the engine I will probably choke ! Thank you anyway for you answer it's also my first time on a forum asking questions !

rockbell said:

THE BOAT IS A COBALT 1993, I was told that the drive had been changed... I could not be more specific but with thw serial #. Please note that my english is second language, so not perfect ! As for the water jet... it was coming from a piece of metal, not fiberglass. I could actually, with a lot of finger, twisting block it. I was just unable to see... And finally I just removed the drive last week end, and there could not possibly be any sign of water as the boat is in my heated garage (with wood stove)...

Click to expand...

The only place water can come in that you can block with your finger and is made of Metal is a hole in the transom assembly.

Yes you will have to pull the engine. It comes out pretty easily especially on your Boat. Does the whole engine hatch with the back seat lift on your model? If yes, there is a lot of room to work.

Thank you for the explanation. Yes on my model the whole hacth and the back seat opens. I will look more into it next week end, since it's at my country house where I do not have internet. I will probably ask more question next week then ! Good evening

I will be back after the 18th.

Before you you do anything else. Turn your steering wheel hard to the left, get a flash light and look inside the transom assembly above the large rubber bellows. Follow the trim sender wires. You should be able to see the rubber grommet on the sender wires and the retainer. Are they still in there? This is the only other leak point on your transom assembly.

If the wires to the trim senders were cut off at the grommet because they were bad and not replaced, there is a chance that the copper inside the case is totally gone and allowing water to pass causing a spray.