Flooded Fuel Tank

I'm a relatively new boat owner, but am somewhat mechanically sound. I had left my boat (1990 Sea Pro 18'6") on water for a period of 5 days without the automatic bilge pump on. The boat took on a lot of water and almost went down. I was able to get it out of the water and drain it. I think a good deal of water and gotten into the fuel tank. I would start up the engine ('03 2-stroke Mercury 150 Optimax) and I would quickly get a Water in Fuel Warning, and it would shut itself down. After emptying the fuel/water filter several times, I decided it may be best to drain the entire tank.
I pumped out 20 something gallons of contaminated fuel through the access point on top of the tank, (where the fuel level indicator sits) this past Saturday, and even the took filter back off and squeezed the fuel out with the primer bulb. I had a few gallons of clean gas (well 10% ethanol) around the house and dumped it in. The engine started up fine, and I began to take it across the lake to fuel up. The Low Fuel warning flickered for a few miles and the engine shut off. I was able to get the boat to a gas pump, and put in about 13 more gallons, but haven't been able to get the engine started again. I put a new fuel//water filter on, and checked a few of the plugs. The two plugs I checked were firing. I tried using a spray of ether, but nothing came of it either. A pressure release valve located next to the cylinder head sprays out a fuel/air mixture.

Any ideas on what to do next?

Re: Flooded Fuel Tank

Fuel/water seperating filters will clog and are not 100 % infallable.

Replace the filter (if you haven't already).

Any water in the fuel lines will push through the injectors into the cyl and short the spark plugs out, take the plugs out, test for spark while they are out to be sure that you haven't coincidentally developed an ignition issue.

Clean and dry the plugs or replace them. BEWARE, if any water IS still within the fuel lines it will again wet one or more plugs again.

Spray that ether on a rag and use it to wipe your hands clean when you are finished (or sniff it before surgery), but DO NOT spray it into your engine!!!!!!!!!!!!!!!!!!!!!! Use pre-mixed fuel, OK?

Re: Flooded Fuel Tank

The fix for a carb engine is relatively simple, you just work the water out of the fuel lines, filters crankcase and carbs. On your optimax, you have very special fuel injectors and air pressure pumps. Get a Merc manual and see if this topic is covered and execute it immediately. Alternatively, you might take it to a merc dealer immediately.

I am just afraid that expensive damage could occur due to the water in the fuel system. I could be wrong......