In water all winter

[Boston Habba]

My son bought an old small house boat that he has to store in the water in Boston Harbor all winter. It has a merc I/O. I know outboards but not I/Os. How do you winterize an I/O that will stay in water all winter? Engine does not run. He is planning on getting it running and restored to live on next summer.
Thanks.

[spareparts]

do you have shore power on the boat? Is the engine closed cooled?

[captpete13]

if it doesn't run all you can really do is drain the water from the block and manifolds. Then fill them as best you can with non toxic antifreeze. If you can leave a droplight on in the engine compartment. the lightbulb will provide enough heat to keep things from freezing in case you missed any water in the block.