It is not likely that the fuel pump (thus also the governor) is lubricated by engine oil. You can tell if it is if you see dedicated oil supply and a return lines connected to the pump. The pump will have a fuel supply line, a fuel return line, and the four lines out to the injectors. If you see...
also worth trying might be 30% strength vinegar. It worked charms on the lichen footprints on my boat's deck, took three applications. Spray it on with a garden sprayer.
Home Depot usually has it