OnBoard Magazine - Issue XI - Summer 2019

This is bad news for boats that are not run often or are stored for a season. A fuel tank storage bulletin released by BP details how the light components in gasoline are lost first as the fuel sits in the tank, which affects both mixture and octane rating. These light components provide valuable benefits during cold start but if they are absent, then the density of the fuel increases which alters the fuel to air ratio resulting in hard or failed starting. Furthermore, this degraded fuel has shown to cause piston damage in high revving 2-stroke and 4-stroke outboard engines. These issues with gasoline instability and the known dangers of ethanol blended fuels have given rise to an ever-growing market of fuel conditioners and stabilizers. Many engine manufacturers, including Yamaha, recommend using marine-specific fuel stabilizer in every tank of fuel. Research has shown that today's ethanol blended fuels and lower octane fuels can begin deteriorating within 15 days depending on air temperature and humidity. Marine engine builders advise installing a water separator for each engine and to keep extra filters on hand for quick replacement in the event of clogging or filter failure. Additional fuel filters, water separators and high-quality fuel stabilizers and conditioners are relatively cheap insurance for your engine(s). BE CAUTIOUS While a quality fuel stabilizer is key in maintaining and prolonging fuel quality, it is important to realize that even the best conditioners and stabilizers will not prevent phase separation or component evaporation if fuel is stored for long periods of time. Furthermore, degraded and stale fuel cannot be reversed or brought back to original quality by dumping extra additive or stabilizer in the tank. Bottom line, if you suspect the fuel in your tank is too old, un-stabilized or emits a foul odor, have it drained completely and fill with fresh, stabilized gasoline before trying to turn the engine over. If the fuel level is lower than half the tank, BP suggests topping off the tank with fresh stabilized gasoline if draining the fuel tank would prove too difficult. The addition of fresh volatile compounds will help mitigate cold start issues and help to combust the older fuel that has now mixed with the fresh fuel. No matter what type of boat you own or its engine configuration, the bottom line is to stay vigilant when refueling. Whether you’re trailering to a road-side gas station or pulling up to a local fuel dock, be careful to select the right grade and always top off the tank with a quality fuel stabilizer in the recommended ratio. A quick second glance, some extra filtration and the recommended amount of fuel treatment will pay dividends to the longevity of your gasoline powered engines. A BIT OF HISTORY ON BLENDED FUELS The early 2000s saw several fronts of concern and issues collide to create a massive storm that resulted in the development of the Renewable Fuel Standard (RFS). Rising crude oil costs, America’s dependency on foreign oil, widely adopted theories of climate change and other circumstances helped drive the need for alternative fuel blending. Corn, a staple crop in the United States that is easily grown in a broad region was chosen as the main source for creating alternative fuels through a fermenting and distilling process that creates ethanol (much like how moonshine is made). Once a technique of blending corn-based ethanol with gasoline was perfected, testing was initiated to determine its safe and practical use. By 2007, E10 (10% ethanol / 90% gasoline) was widely available at most filling stations throughout the country and within a couple years it became increasingly difficult to find a gas station that still carried pure ethanol-free gasoline. It didn’t take long for issues to start appearing in a variety of engines and so the ethanol blended fuel debate became quite a contentious issue in the U.S. ..non-ethanol fuel can still cause issues in all types of gasoline engines... 45 SUMMER 2019