Funky running 2001 Mercury 200 efi

Scubadude918

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Joined
Jul 25, 2017
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3
First time on this site. Thanks in advance for all of the knowledge you people share. It has helped me in so many ways.

So about a year ago, I bought this boat with a Mercury 200efi engine on it. It ran wonderfully for that year. I encountered high seas and this forced water into my fuel tank through my fuel tank vent. I later stalled out in the inlet and had to pump a gallon of water out of my fuel tank and drain my separator (responcibly of course (thank you gallon water jug!)) several times until I was able to motor back to dock. It ran fine for the rest of the year.

That's the backstory. Here's the new story.
This year after putting my boat back on the water, I've had rough idle, stalling on occasion at idle at inopportune times, and now the new guest to the party is after being in a no wake zone for a little bit, and then throttling up, it gets stuck at about 2500 RPMs and Boggs. I have to bring the throttle back to neutral and slam it to Full Throttle in order to get the engine running at normal RPMs for plane. While on plane I have no issue. I pulled the spark plug wires from each cylinder and noticed very little change on One Bank of cylinders. The other Bank of cylinders I noticed a definitive change at idle. I've replaced the spark plugs, replaced the water fuel separator and I'm still having the same issue.

Anyone have any ideas? Similar issues?
Thanks anyone who can help!

P.S.
There is no water in the fuel tank and has probably ran about 10 hours after the water intrusion, before this new problem.
 
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Scubadude918

Recruit
Joined
Jul 25, 2017
Messages
3
I'm gonna check the injectors this week. I've already checked for spark. Definitely getting that.
 
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