Hydrolocked in the parkinglot

[gica]

Weird title but yesterday I spent all day working to finish my two 2-stroke waverunners and only around 10pm I decided to go to my 1997 Maxum 5.7L to just start it and clean it a bit for the next morning.
to my surprise the engine would try to crank and lock up. I thought it was the battery being low. So enabled the dual charger and waited, tried again and same thing. I opened up the engine area at the transom and under the engine there was a lot of black, nasty water touching the engine, and of course the drain screw was on(my bad). I remember after going fishing a few month back, before Covid, I pressure washed the floor and never thought I had the drain blocked(brain fart). so cleaned up the engine compartment and tried again, no luck the starter sounded like it wasn't engaging(wasn't a click, click sound) weird sound as if it was free spinning and not touching the flywheel. So my friend suggested that it may be hydro locked.
I said how the heck I started it a month before when I did the pressure spraying. I did have water running at the engine.
So how the heck did I get the water to stay in the cylinders, yes I took off all 8 plugs and spun the engine from the main pulley and water rushed right out.
I read about the risers getting rusted being cast iron, manifolds to go with, some said something about the risers being too low sometimes, but only if coming to a quick stop on water and engine overheated it could cause water to get in. Not my case here, never had that problem, and only the last trip was on salt water. Cleaned it for 20min right afterwards.
what do you guys suggest besides getting the starter out and replacing it.
By the way the oil doesn't look contaminated but I will change it with the filter.
Sorry for the long plot but wanted to fully explain.

[Turtle Blues]

Have had the same issue from cover drooping over seam in seats allowing water to run into air box all winter.

Removed plugs, filled cylinders with oil, laid rags over engine and spun engine in short bursts with starter. Repeated a couple of times and then installed new oil and plugs,cleaned up the engine and bilge.
10 years later that engine is still running. Not super high on compression but solid and not excessive on oil consumption.

[gica]

It's weird that my starter locked up so I had to spin by hand. And it all happened in the parking lot 4 month after last time I took it out. I did pressure washed it with the drain plug on. So the water from there was my own doing. But the water in the engine, maybe I left the hose on after shutting the motor off. Maybe raisers rusted, i don't think it went in through the carb since it has a plastic cover on.