Repairing leaky block on 1988 omc 3.0

I recently bought a 1988 bayliner with a 3.0 omc stern drive, only to discover that it has a cracked block.
According to the boat shop, I need to replace the motor, but since it is an old boat, that is not a viable financial option. The leak appears to be toward the top of the block, just below the manifold, but it is very difficult to see without removing the manifold. There does not appear to be any water in the oil, just water coming out of the block. I've read a lot of good things about JB Weld being able to fix cracked blocks permanently if done right. Do you think it is could work for my problem? Also, is there anything special I need to know about removing and replacing the manifold?
I'd really appreciate any and all advice!

Re: Repairing leaky block on 1988 omc 3.0

in my opinion, you may be able to get the block to last another season or two with JB weld, however keep an eye out for a 3.0 on ebay or craigslist. do you really want to trust your boating to some epoxy?

Re: Repairing leaky block on 1988 omc 3.0

3.0 can be bought for about 900 used. Takes one day and a bobcat or a couple strong guys to swap.

Chuck

Re: Repairing leaky block on 1988 omc 3.0

1) Remove the manifold.
2) Thorough inspection of the block AND manifold to make sure the manifold isn't the source of the leak. If it is replace the manifold.
If the block is cracked, go to step 3. If the crack extends all the way up to the block/cylinder head mating surface you will not be able to fully seal the leak.
3) Drill and tap a hole at the top and bottom of the crack to prevent it from getting bigger.
4) Using a dremel tool or small die grinder, clean up the crack and make it a "V" shape.
5) Apply JB weld to the plugs that will go into the two holes and then spread a liberal amount of JB to the crack.
6) Allow a couple of days for the JB to fully cure.
7) Install the manifold.