If by flooded you mean with water. And that water was never properly cleared from the motor. You are basically looking at a good possibility of a complete motor rebuild. The smallest amount of water left in the motor will ruin the crank and rod brgs.
Have you tried to turn it by hand from the shaft coupling at the rear of the motor to see if it's locked up? May have to remove the cover. Basically you'll need to at least remove the head and cyl's to determine internal condition. And move forward from there based on what you find. Mark cyl's 1,2,3 before removal to keep arrangement to Pistons in case it's ok inside.
If you don't have a manual look above in "general pwc discussion" manuals the first post has a link to downloadable service manuals.
That could be the starter is seized up or the solenoid is bad. I'm guessing starter.
I would start by removing the cover from the shaft coupling at the rear of the motor.(BLK plastic cover) this will allow you to turn the motor by hand. You may need to remove the plugs to turn it. I'd also put either some 2stroke oil or marvel mystery oil in each cyl plug hole. About 2 tablespoons in each.