99 1900 sr i/o not starting after taking on water

[Burton]

I went camping and drove my boat to a mooring where it sat for 3 days because of nonstop rain. When I went to retrieve my boat it was full of water to the floor level. It would not start. I was towed to the launch and put it on my trailer where it drained for 35min.I'm assuming the pump never switched on, and I think there's water somewhere. I'm new at being a boat owner.
In the gas?
Spark plugs?
I obviously tried to start it when the engine was sitting in the water(1/3). Did I make it worse?
Where do I start?
It's been 7 days I had hoped it dried out, but it's still not starting. However, it is turning over, but when I let the key go it let's out a puff nose and dies

[mmwjr]

What engine do you have? Was the starter and or alternator under water? It sounds like the engine turns over but doesn’t fire up; correct? Is the run safety switch in the run position? Can you measure the voltage on the + terminal of the ignition coil with the key in the run position and let us know the reading?

[Burton]

It's a mercruiser 5.0. The alternator nor the starter was submerged. It sounds like it's gonna start then putts out. I took the fuel water superstore off and see if there was water in the gas... no. I checked the oil and saw that it was 3in above full. Do you think that all of the water it took on and almost standing up on its backside the oil filter being submerged allowed water in the engine? Does this happen?

[Burton]

Seperator* not superstore

[Burton]

I'd measure voltage but my reader is at work.

[mmwjr]

To much oil in the crankcase is an issue but doubt that occurred from high bilge water as the system is sealed. You may have another issue such as bad/ leaking exhaust. How old are the manifolds and risers? Salt or freshwater?

[Burton]

I'm not sure how old they are. I bought the boat used last year.
I disconnected the distributer cap and reconnected, then I added fuel cleaner... it started up. Ehhhh who knows lol 😆

[mmwjr]

So it’s running ok?

[Burton]

It started up and ran for 3 minutes. I shut it down and started it up again. I'll take it out this weekend. I'm starting to think coincidentally even though my boat took on water im pretty sure it was bad gas. I hauled it on a2.5hr drive. When I was near my campsite I filled the boat up before putting it in the lake.

[mmwjr]

Based on what you said about the oil being 3” high you should address this with an oil change. But first was the boat sitting level what you checked it?

[Burton]

I have a siphon pump.. I'll take some out and see if there's water in it after I extract the overflow. Maybe it was high because the boat wasn't hot? I'll check it before I take it out. It was an inch not 3 inches. My mistake... it's a long dipstick.

[mmwjr]

Oil level doesn’t really change with engine temperature. Is the oil clean looking on the dipstick?