Water Filling Up Bilge when Reversing

[woodman7975]

I have a 1988 Sea Ray Seville with a 4.3L Mercruiser. I noticed that whenever I put it in reverse and back it off the lift, or reverse in general my bilge fills up with water. It only seems to happen when I reverse, I can be on the water all day pulling tubers or drive around and I do not get any water in. I had a buddy drive while I lifted the cover and I can see it coming in when reversing, but I cannot tell from where. It looks like it is down towards the bottom of the outdrive, but I cannot really see so it could be from anywhere. I could see enough to verify that it is not coming from the drive shaft. I was able to inspect the outdrive as much as I could while it was on the lift and it looks like all the bellows except for the exhaust are in good shape and connected properly. The exhaust bellow does look old, but I could not find any noticeable tears. I was also told that water could not get in through the exhaust bellow, is that correct? Any suggestions on what to check next?

Also, I ran the engine in idle, forward and reverse while sitting on the lift and I did not get any water in. I also lowered it down enough to put the drain plug under water and it did not leak in through the drain plug.

 

[Bondo]

Ayuh,...... Welcome Aboard,..... Yer transom is Rotten, 'n the boat is unsafe, til fixed,....

When in reverse in the water, the prop pulls the drive away from the transom, allowin' water to rush in through the big gap formed,.....

 

[woodman7975]

Is there anyway to check this without pulling off the outdrive? Also, another issue that may be contributing to this is a stupid mistake I made earlier this year. The boat is parked on a steep incline and when I went to pull the plugs to drain the water out of the engine it flipped backwards and got caught on the skeg, which I am sure pulled the outdrive mount away from the transom. I also ran a bead of caulk around the outdrive mount to see if it was pulling away and I did not see any cracks in the caulk. I had a few stress cracks around the drain plug, but none where the outdrive mounts. I repaired the stress cracks around the drain plug and pulled off the drain plug in the process and did see of feel any rot. Not that there isn't any, it is just what I saw at that location.

 

[woodman7975]

Also, if the transom is rotted, any ideas on cost to repair?

 

[AShipShow]

Where are your bilge vents? Is it possible water is pushing up against the boat high enough to be coming in thru your bilge vent? I've stopped quickly before and the wave that comes up and hits the back of the boat has come up high enough to go in my vent tube and had me confused.

 

[woodman7975]

The vents are on the side above the rub rail. I thought about this and I did not see any water coming out of them. When I saw the water coming it, it was definitely coming in thought the transom or drive.

 

[Maclin]

The vents are on the side above the rub rail. I thought about this and I did not see any water coming out of them. When I saw the water coming it, it was definitely coming in thought the transom or drive.

Well, you looked and saw that, and the first advice is usually "look to see where it is coming from".

If the water rushes in as bad as you describe, then you should be able to see some movement out on the transom mount if it is tilted all the way up and you get some good leverage and pull up on the drive, the transom mount should not move. You will probably see a gap open at the bottom as it moves slightly away from the transom.

 

[woodman7975]

I will try to pull up on it tonight and see if I can get any movement. The problem is that I can see water coming in, but I can't see far back enough to see from where exactly. Are there bolts on the backside that you can reach to tighten? If there is rot, would the bolt pull through or deflect significantly?

 

[H20Rat]

Does it happen if you are just floating in the water, engine off? Or do you have to actually back up? So far doesn't sound like transom, but can't rule it out. Another check is to carefully stand on your outdrive when it is on the trailer. Shouldn't see any flex.

And correct, water can't generally come in through the exhaust bellow unless you have other problems. The other two bellows on the other hand, they can let in lots of water!

 

[woodman7975]

It does not happen when I am just floating or in forward, only in reverse. The other two bellows look like they have been replaced recently. It is kind of tight, so it is tough to really see if there are any issues with them. I did notice that what I believe is the shift cable bellow, it is the smallest of the three, one end only has a zip tie holding it on and not a hose clamp. I can also move the one end up and down, but wouldn't that be an issue if I was moving forward also?

 

[79Renken]

Is it possible it is a bad drive shaft/u joint bellows and when in reverse it is low enough to allow water to enter?

 

[AShipShow]

Zip tie on the shift cable bellows is okay... thats usually what comes with the replacements.

Thinking its got to be something with the water level rising on the transom when in reverse.. Maybe leaking seal between hull and cap?

 

[hoowahfun]

Is the wiring still there for the trim position/feedback sensors? Could be someone pulled it out and never plugged the hole in the transom assembly and when you back up it pushes up through that hole. Just a guess.

 

[Bondo]

The problem is that I can see water coming in, but I can't see far back enough to see from where exactly.

Ayuh,..... A digital camera will put yer eyes, where yer head won't fit,.....

If it's on the wagon, 'n not in the water,....
Hook up to the trailer, raise the drive, thrown down some blockin' under the drive, 'n hit the down button til the trim loads up abit,.....
Then look for a gap at the bottom of the transom housin',.....

 

[89retta]

Since it only happens in reverse lifting up on it wont help you see the crack. Lower the drive and push the bottom of the drive forward towards the bow. This will simulate the action of the boat in reverse. Look around the top and sides of the transom shield for openings where water can come in

 

[JASinIL2006]

Since it only happens in reverse lifting up on it wont help you see the crack. Lower the drive and push the bottom of the drive forward towards the bow. This will simulate the action of the boat in reverse. Look around the top and sides of the transom shield for openings where water can come in

Wouldn't this be backwards? When the drive is in reverse, it's pulling away from the boat, i.e., lifting the drive. When it's in forward, it's pushing the boat, similar to pushing down on the drive. Or am I misunderstanding what you wrote?

 

[89retta]

Yes you are correct. Sorry I had a brain fart