Veronica was built in 1974. Her fuel tanks had never been opened up. In 2008, we started to experience some problems. We couldn't tell if it was bad, old fuel, some bad new fuel, a fuel feed problem or an injector problem. First, I had designed, fabricated and built a fuel polishing system. It appears overly complex, but with it I can run the engine and genset, bleed the engine and genset, polish the fuel, fill the fuel filters, and vacuum check every component in the fuel system. The polishing system helped, but did not cure the problem. Fortunately, access to the tops of the fuel tanks is not that difficult, if you are slender, young and flexible. Fortunately, one of the experienced hands at the yard was. Lucky guy. We cut big holes in the top of the tank, one over each bay (the volume between the baffles) after we emptied the fuel tank. That was easy with the fuel polishing system. I would advocate using a really long hose to a receptacle ashore so as to keep diesel fuel smell out of the boat. Once the tanks were opened and ventilated, we sucked the black grunge off the bottom of the tank. I think it was just 35 years of bacterial residue. The metal on the bottom was bright, no rust, validating Willard's bottom feed approach. The one thing I did not do that I wish I had, was to replace the fuel shutoff valve while the tank was empty. There is a tiny weep, which went unnoticed until recently which could have been easily cured while the tank was empty. Again, this did not completely cure the fuel feed problem. The only remaining culprit was the injection system. Bob Salmons Veronica Willard 40 RPH