Stern drive water leak HELP

[rapdron]

"Hello everyone.

I'm n

"Hello everyone.

I'm new to this board, looking for some expert advice on finding a major water leak.

I just finished putting a new GM 5.7L power pack motor and a rebuilt Mercruiser Alpha into my nephew's 1989 Wellcraft 233 Eclipse.

Long story short, boat was in the water 3 years ago, everything working fine.
That winter, he put it in the back lot of his auto repair shop, covered for the winter.

Over the winter, Someone stole the outdrive and carb.

The motor box was left off, and rain and snow got into motor. Motor seized.

Last week, we finished putting in a new motor and an Alpha drive.

Yesterday, after running on land for about 2 hours off and on to break in motor and do final checks, we launched the boat for it's maiden voyage.
Ran boat for about 1/2 hour on water, everything looked and sounded great.
They left to dock it at the marina, about a hours ride from the ramp. Everything working and sounding great.
Docked the boat at marina, boat quickly started taking on water around where engine coupler and shaft meet. We don't know if it was taking on any water during the hours ride while on the water.
Yes, the drain plug was in!
We put it back on the trailer, took it back to shop and looked for obvious damage. None visible
Ran motor with ear muffs, no water leaks and engine runs fine.
Pulled off outdrive, removed and checked drive bellows, exhaust bellows, and shifter bellows.
Every clamp was tight, not tears or cracks in anything. Water hose inside housing tight, no cracks or leaks. The plastic tube where it goes through the housing looks ok, o-ring is good.

I have no idea where else to look.

The bilge pump had all it could do to try to keep up with the leak; it was that bad, so it has to be something major.

There was no problem with any water leaks the last time the boat was in the water (3 years ago), so I'm guessing it has to be something we did. I just can't find it.
An help will be appreciated!

I plan on putting in all new bellows, water hose and drive to housing o-rings and gaskets this week and putting the stern in the water on the trailer to see if I can see if I can find the leak.

Thanks, Ron"

 

[bondo]

"[b]"The bilge pump had al

""The bilge pump had all it could do to try to keep up with the leak; it was that bad, so it has to be something major."

Ayuh,....

With a Leak that Bad,....
It shouldn't be too hard to find,...
And,...
The Only way to do it is,... Look...."

 

[bwingler]

"My old boat did that and it w

"My old boat did that and it was the bellows, it looked fine while it was still on the boat but when i got it off it was cracked in one of the folds at the top. Running on muffs wont show a u-joint bellows leak."

 

[johnkillcare]

Don't know if you have fou

Don't know if you have found the problem yet but I just had the same problem and it turned out to be a corroded aluminium bolt where the transom plate bolts on (the port side bottom bolt) The bolt had corroded right through and eventually broke so the head was just sitting in the hole with water leaking past it into the boat.

 

[rapdron]

"Hi John
I wound up replacing

"Hi John
I wound up replacing the outer gimble housing.
It turned out to be a process of elimination, since the the water inlet hose, driveshaft, exhaust and lower shifter cable bellows checked out OK.
The middle bolt on the starboard side had corroded to where it was letting water past the gimble transom seal, and eventually had eaten through the housing.
Mercruiser makes a bolt kit just for that purpose.
We had to pull the motor to get to the inside bolts in order to replace the housing, but there was no other option. Not as bad a job as you might expect. We left most everything attached to the motor, removing the exhaust riser bellows, the p/s hoses, shifter & throttle cables and the main wiring harness and the starter wires. Took about 5 hours start to finish with 2 people.

You couldn't really see the hole with the housing still in the boat, but it was quite obvious once it was removed.

A lot of work, but at least now everything, including the bellows and outer housing is new!"