I have a 1988 Bayliner that has not been run in over 10 years. How can I purge and clean the fuel cell?

-I am certain that there is some serious residue and really bad gas left in the cell. IF I can clean this out then I would consider having the engine repaired.you may be attacking you problem backwards.is it an i/o or outboard?get the engine running on a test tank first,and see if it's even worth fixing.if it's an i/o you may have issues with manifolds/risers,boots/bellows,etc. if it's an outboard the entire fuel system will need to be cleaned,including carbs. if the engine checks out,remove the anti siphon valve at the fuel tank and replace it with a hose barb,then siphon as much fuel out as you can with the bow raised.this will get most of the fuel out.remove the fuel sender and you will be able to get a hose down to the bottom of the tank to get the remaining fuel out.it helps if you jack up one side of the trailer and raise the bow so the fuel will run to one corner of the tank if it's on a trailer.it wouldn't hurt to put 5 gallons of fresh fuel in and repeat the process.check the fuel sender and replace with a new one if needed.install a water separating fuel filter if not already equipped.be careful and have a fire extingusher close by.even 10 year old fuel will blow your a$$ up. don't forget to check the anti siphon valve and replace if needed.