MTBE has a superior capability to "oxygenate" fuel, reducing emissions. Unfortunately, the chemical has been associated with ground water pollution and is a growing liability issue for petroleum refiners. Ethanol solves the ground water issue, since it has a very short life in the environment before it is broken down chemically by nature. As a result, most refining companies are switching to ethanol-blended fuels. Those fuels, however, present a challenge for boaters.
While fuel blends using as much as 10 percent ethanol are approved for use in some outboards, there are three facts boaters should know:
1. Ethanol attracts and absorbs moisture from the air. That means boaters will likely face more fuel contamination issues from water absorbed through their fuel tank vents.
2. Ethanol is a solvent and can dissolve varnish and other material in fuel systems. In some cases, it will dissolve components of the fuel system itself, such as fiberglass fuel tanks.
3. Because of that, boaters and builders can:
• Use fuel system components that are compatible with ethanol blends or replace those in use that are not compatible.
• Install a Yamaha mini-10 filter™ or Ten Micron Filter. The Ten Micron filter is designed for use on boats with outboards larger than 115hp. The new, more compact mini-10 is designed to fit the confines of smaller boats. It was created to filter out contaminants and separate water from the fuel. The mini-10 features an aluminum head and is made from coated steel inside and painted steel outside to address corrosion concerns. It also meets all U.S Coast Guard and ABYC requirements for fuel systems as related to safety.
