OnBoard Magazine - Issue XI - Summer 2019

N othing wrecks a day on the water like an engine that refuses to start or runs poorly and can’t build RPMs. Whether you’re running a high-powered center console, an older inboard, or just trying to get the tender back up and running, poor fuel quality can be the culprit of unfavorable operating conditions or even an engine that flat out refuses to turn over. Even the newest engine technology and components can’t mitigate the ill effects of tainted fuel, so let’s discuss some of the ways an operator can lessen or even eliminate these issues. Something that has been looming on the horizon and coming in and out of the headlines for the last several years is the introduction of higher concentrations of ethanol blended gasoline. Claims of pump-ready fuels blended with anywhere from 15%-30% ethanol (popularly known as E15 and E30) are now trickling out to gas stations who are willing to adopt the higher blends. Dozens of organizations including the NMMA have lobbied the fight against these higher concentrations due to concerns of further engine damage for boats, other small engines and even automobiles produced before a certain model year. However, battles have been lost along the way and legislation has pushed these higher blends through different approval processes allowing their adoption. A SPECIFIC SHELF-LIFE For ethanol blended fuels, the ethanol attracts moisture which becomes more problematic in humid climates like the all- season boating state of Florida. The more water the ethanol attracts, the heavier it becomes until a process known as phase separation occurs, which breaks the bonds of the gasoline and ethanol, allowing the ethanol and water to settle at the bottom of the fuel tank. This can cause rust in a metal tank along with the softening and breakdown of unprotected fiberglass tanks. Additionally, ethanol that phase separates and is left to sit in a tank or within the fuel system will form a heavy brown skin that can cause filter clogging, pump and injector failures or worse. Although aluminum fuel tanks will not rust, they are not immune to the heavy brown sludge that forms from the ethanol in fuel. Due to the known issues with ethanol blended fuels, many marinas choose to only dispense non-ethanol gasoline, but that’s not always the case. Sticking to only marine- grade fuel in your boat can go a long way in warding off the gas gremlins, but that’s easier said than done in some regions. Additionally, non-ethanol fuel can still cause issues in all types of gasoline engines, including marine inboards and outboards. According to Sunoco’s Race Fuel division, lower octane fuels will degrade much quicker than higher octane fuels due to the presence of unrefined hydrocarbons. For example, 87 octane fuel which is allowed to vent to atmosphere will lose vapor pressure allowing hydrocarbons to evaporate causing the fuel to go stale quicker. Even fuel that is stored properly in an air tight environment can go stale within 3 months. FUEL CONDITIONERS, STABILIZERS AND THE E15 DEBATE & DUMP PUMP 44 BLUEWATER