Water intrusion...

[itsacrazyasian]

Like many of the other threads started here about a boat taking on water, i have atleast done a little bit of digging before i tossed a post on here.

The boat is a 1994 Aquatron 22ft with a 4.3 v6, alpha one, gen 2. I traded a motorcycle that was sitting in my shop (after i got hit by a car on it years ago) for it. Owner had reciepts of a reman longblock replacement a few years ago, not many hours put on the motor since. I installed a new fuel pump to get her running and she runs great on muffs. New belts just in case. Along with the reciepts, i found that the outdrive bellows were replaced recently. They didn't do the exhaust bellows, but i went ahead and put one on since where i usually go out, there are strict noise regulations. I inspected the rest of the boots and they looked great. I saw a little bit of gear oil coming through the transom plate, but we'll get there.

Anyway, i wanted to wet test the boat so i backed it in a local pond. Sure enough its taking on water. About a gallon every 6-8 minutes. It looked like it was from the exhaust y pipe since it was down real low. So i took it back out of the water, took the exhaust bellow back off and shoved a garden hose with a cap on the end of the bellow. No water intrusion inside the boat. Getting pissed off, i yanked the outdrive. but left the gimble ring on just to have a look at the inside of the ujoint bellow. perfect, no gear oil either. guess what i saw was residual from prior to the repairs.

Put it all back together with new seals. Jack the bow of the boat up high and fill the bilge with water. I filled it up to the bottom of the starter and i didn't see any water coming through.

I wet test the boat again, coming from the same spot....

Any suggestions and sorry for the long post.

Patrick

and i was getting ready to pull the gimble ring off just to look at the boots. I mean they look new, nice and soft. No dry rot, not even a sign of it. the water isn't coming from around the driveshaft, its below it... Anyway, one of the hinge pins is stripped on the inside so my tool won't even grab it...

Now i remember why i sold my Carver.

 

[Bt Doctur]

Re: Water intrusion...

did you remember to plug the exaust relief ports too. try squirting water around the transom area while looking inside.
'might be a loose/rotted transom or transom gasket .
when I get hinge pins like that i have a welder weld a nut to the end of it.the welding heat cuts the red loctite.

 

[sharkin95]

Re: Water intrusion...

there are only a few ways on a alpha 1 you get water comming in..drive shaft bellows, lower shift cable bellows, water intake hose or a loose drain plug. your location tells me lower shift cable bellows.

 

[itsacrazyasian]

Re: Water intrusion...

No, i did not plug lower exhaust ports. Guess i need to try that huh? Based on how fast the water was coming in, i didn't think i needed to plug them as the hose moved alot of water at fairly high pressure.

The transom seems solid. No hollow spots where i can tell. For giggles, i sealed around the transom bracket with 3m 5200 and let it cure. I forgot to mention that. Its just driving me nuts.

Its one of the reasons why i actually traded, seems like this is one of the easiest outdrives to work on, especially compared to the volvo pentas i had before.

I'll find some rubber plugs and shove the garden hose in the exhaust bellow again and see what happens. With my luck its going to wind up in the engine.

 

[Bt Doctur]

Re: Water intrusion...

or remove the risers ,plug the exaust and idle ports with rags, put water in the exaust Y pipe, see where it leaks out.

 

[itsacrazyasian]

Re: Water intrusion...

well i finally had the time to take a extractor to the hinge pin... The driveshaft bellow looked great. As did the rest of the assembly. Theres very, very little corrosion on the entire unit, thought it was coming in around the water pipe as it had a little bit of play in it. Turns out i have a small pinhole in a corner of the transom plate. My little pocket screwdriver tip is about the diameter of the hole but its a hole none the less...

I have a feeling this is going to be a pita to replace. Most of my sterndrive experience is with Volvo-Penta outdrives. This is my first Mercruiser. I'm assuming the engine will be coming out to say the very least.

 

[Howard Sterndrive]

Re: Water intrusion...

there's another water entry point down low right near the Y pipe no one ever seems to mention - the gasket on the trim hydraulic manifold

I just pulled my engine and replaced my Y pipe o-ring... I'm *pretty sure* that was the culprit (although I wish I could have seen stronger evidence- it was hard and sort of flat with 1 sort of 'nick' in it). But while it was out, I got looking at the manifold for the trim hoses... that could totally let water in...and maybe I pulled the engine for nothing. I unbolted it and put a new gasket on there with a ton of sealant just for kicks.

Mine would not leak at all when I put the drive back on, engine out, left the Y pipe on and backed it into the lake - I lay face first in the bilge and watched it for 90 minutes....water right up to the shutters.....everything bone dry. trimmed up, trimmed down, steered, shifted about 2 dozen times each. dry.
yet, when the engine was in... it would take on water...sometimes had to be running making me think it was exhaust water, but other random times, it would continue to take water in after the engine was shut off....as in all night... the bilge pump would run every 90 minutes or so....other times, nothing...frustrating
I wanted to look at my transom closely anyway...luckily it's solid as a rock, but there's about 10 places water can come in these things... It's crazy really, in my opinion. That 90 minutes of contemplation of how everything is assembled in there made me appreciate my OMC stringer a bit.

oh well, this was , um... fun? bilge is like a desert now, and good to learn my transom is in good shape. I cleaned everything up anyways, installed a second bilge pump nicely and got rid of the stupid screws Bayliner uses to clamp the power trim hoses to the transom down low (why? are those hoses going somewhere???) I cleaned and filled the holes carefully.