1999 Powerquest 28' silencer w/502 MAG MPI... On Sunday I filled up the gas tank (completely full for the first time) (I've put gas in it many other times, just not completely full). Got home and took off the water circulation pump to replace it. Uncovered the boat on Wednesday once the new pump came in and the boat reeked of strong gas fumes. Replaced the pump and covered it back up. Uncovered last night, again really strong fuel smell. Any ideas? Is it because I filled up the tank all the way? Is there another vent somewhere else besides the one on the exterior of the boat? I've never had this happen before, but I've never topped off the tank before. I didn't do anything fuel related (that I know of) when replacing the water circulation pump.

Probably a leaking gasket on the fuel level sending unit.

i hope its just a seal at the sending unit or something small like that . back in april i noticed gas in my bilge after checking everything i ended up having a hole in the bottom of my tank and had to replace it . no fun in a AT , glassed in floor . hope you find it soon .

If you filled the tank full and the ambient temperature increased then the fuel expanded and flowed out the vent. Siphon some out to see if it goes away if you can find no obvious other signs of leakage.

Apex: I have a 38 Powerquest and the inspection hatch for the rear of my gas tank is under my back seat. SAME exact issue. Only smelled fuel after full fill up. It was the sending unit gasket and is a simple fix. I bet you have the same problem. Pull the hatch and take a look.

Thanks for all the replies. It was the sending unit gasket. Got it fixed! I had to make a gasket in order to get it fixed before the weekend. Anyone know where I can buy a new gasket? thanks