Engine toast? Engine Einsteins! I need advice

[1970_mgb]

Any help would be appreciated

Background:
At the end of last season boat suddenly lost power, but would start.
Pulling the head I found a hole burnt in PTO piston so boat was put away for the winter.
After pulling off the cylinders, now I have found the PTO side of the case has a good cupful of water/oil/gas inside but the mag piston and crank case look normal, with just a bit of oil at the bottom.
The lower end of the PTO side has very light rust on the counterweight but crank end rollers what I can see of them look fine. You can actually see the waterline on the counterweights in the pics.

Questions:
Am wondering how water got into only one side of the crankcase. Crack in casing to water jaket , failed gasket?
I am assuming that water in the crank = contaminated fuel mixture = lean condition = burnt piston. Make sense?

What is my next step?
The first pic shows condition of the Mag side case , second id the PTO (failed ) side

Thanks

 

[Seadoobuddy]

Hi sorry for your problem.
Needless to say that over the winter would have been the best time to rebuild the motor. Send it to SBT or another that''s mention here in the forum.
If it was a cracked block they will send you a new one and then rebuild/repair yours to send to someone else later. If not cracked then find the source of the water so it doesn't happen again.

 

[howie099]

Did you check to make sure you don't have water in the fuel also? It sounds like a a crack or gasket leaking. The shop that fixes it should be able to tell you.

 

[Dr Honda]

Rust = DONE.

If you try to use that crank... I bet it will eat itself in short order. It wouldn't be worth my time (being stranded in the middle of a lake) to even mess with it.