Have built in 12 gallon aluminum tank. full of Amoco supreme/stabil but set up for approx. 2 years. Suprisingly though, the gas doesn't have that smell. Seems ok but i am not about to trust it.<br />Have drained the tank best i could tru fuel line and i know must be residue in bottom. Need to pull the tank for sure, but doesn't have access other than fill tube and sending unit for guage. Should i attempt to clean it or just buy a new plastic one?