Diesel bug is the boat owner’s enemy. This microscopic collection of yeasts, moulds and bacteria absorbed from the air lives for 24 hours and doubles in numbers every 20 minutes. It’s the dead organisms that build up to make that sludge.
Dirty fuel, or sludge, can get into fuel lines, block filters and injectors, cause internal corrosion, reduce horsepower and even cause engine failure. And the fuel tank is a wonderful place for them to live… access to food (carbon), water (so they can grow), oxygen to breathe and the perfect temperature. Sold!
So when Stu Davies warned me we might find diesel bug in the tanks of our Maxi 84 Project Boat, I waited with bated breath. The 28ft cruiser had been sitting in a boatyard for 18 months, its fuel tanks half empty.
“Diesel bug grows on the interface between water and the diesel,” Stu explained, shining a torch in the fuel tank, and illuminating a layer of ominous black crud. “You can see where condensation has trickled down the inlet pipe, gone into the tank, and where it’s run to the lowest part of the tank. The black marks are where the bugs have been.”
“Been?” This sounded promising. “So the bugs aren’t there anymore?”
“I don’t think that bug is live,” he clarified. “OK, if you want to be really pedantic, take the tank out and steam-clean it next season, but looking at thethat bug is going to affect it.”
