[bigeasy1]

I had a fuel leak around the sending unit on my fuel tank in my Tsunami, and had some gas spill into the bilge when we accidentely overfilled the tank at the gas dock.
It took many cleanings with several cleaners to get the odor of raw fuel out of the bilge.

I had the best luck with two applications of bilge cleaner followed up by a couple more cleanings with the degreaser called Greased lightening.I got right in there with the garen hose and flushed it out many times.
Once you get it as clean as possible open up any hatches and motor boxes and let it air out.I also found a fan placed in the bilge helped to get the smell out. If you can pull the hatch above the fuel tank, that will also help to vent any odors and fumes, and expose any leaks in hoses etc.

Did you try Simple Green? my mechanic said he uses it to get fuel spill odors out of the bilges and it works pretty well.
Time is the key, that fuel smell can linger for quite some time even after you clean it very well.Even a tiny amount of gasoline will leave a residual odor for a while

When I did the restoration of my Tsunami I made the floor in the compartment forward of the fuel tank removable so I was able to access most all of the keel and bilge area from the stern to the cabin and expose it to the air.

It just takes time, but degreasers like simple green, greased lightening,or another liked Super clean (purple container) should work well. Good luck