Loss of Power DD 8.2s

[Double D]

Boat sat for a month with 1/2 tank of fuel with starter/electrical problems on the starboard side. Got that resolved, and both engines idle fine

However, on the test ride, I have no power from either engine, and tons of black smoke. I am thinking algae in the fuel

I'm going to put in biocide and change filters. Should I top off the tanks? Get fuel polished? Any other steps?

Thanks

[000's]

Not a mechanic,racors will tell the story on algea,maybe water,may need to flush tanks, new fuel filters primary, secondary,racors or what ever you have,someone here will help Im Sure,before you call a mechanic.

[tunamike]

I left my boat (with 8.2's) down in Fla. for a few months, and when we headed north the boat wouldn't plane and the port engine had black exhaust smoke real bad. With the engine off I reached in the aircleaner and found the turbo was frozen. Just took a wrench and turned it by hand to break it free. Worked fine after that.

[JShelton]

Check your turbos. I'm no expert either, but had a similar problem with my Cummins and the turbo was stuck on one engine. Black smoke means you getting fuel, but not enough air.