Motor sitting full of water for 10 months

I'd imagine rust has already eaten up a bunch of internal parts.

But, I'd pickle it. Fill something with diesel that you can sit it in. That'll fill/cover it with diesel and get the water out/off of it. Then drain, and dry with air hose in every nook and cranny. Re-assemble with new spark plugs, put some gas in it, cross you fingers and try to start it.

What kind of motor are talking about here?

Outboard? Carb or Fuel injected?

4 wheeler? Lawn mower?

Remove the plugs, see if it can be turned over by hand. If not fill the cylinders with penetrating oil, let sit for a few days then see if you can break it free. If not let it sit some more. May need to use a breaker bar, but don't try too hard.


Turn it by hand a few times to see if it is binding at all. If not put the plugs in and see if you can get it to start. If it will start and run, add a can of seafoam to a 1 gallon gas tank (mixed if it is 2 stroke). Run it good on that mixture until 1/2 is gone. Let is sit for a few hours. Run it thru the other 1/2, let it sit for a few hours. Run it with fresh gas (mixed if is a 2 stroke). If the rings are sticking this should help free them up. You will smoke out the neighborhood and help control the mosquito population too.


If it was mine, and anything was locked up, I would patiently wait for the penetrating oil to free it up and pull the heads to see if the cylinder walls have any rust.

That is a long time for it to be sitting full of water, and there is a good chance nothing is going to help!

In before Seafoam.

ETA: Dang. Too late.

Hate to say this, but if you had cylinders full of water you will have some in the bottom end. Rings have gaps in them, and water would have seeped by. What kind of engine?