Over the last seven years, Jim Petersen, director of service for Port Harbor Marine in South Portland, Maine, has seen his share of ethanol-related problems.
Outboard engines can abruptly stop working while in use or fail to start. Other issues with fuel tanks and lines also have been reported. While it’s true these issues occur most often on large powerboats, small motors used on dinghies, for example, are just as susceptible to ethanol fuel issues. In fact, the less often an engine is used, the greater the chance for a problem.
“Boats used all the time that have fuel added to them every two or three weeks, we don’t see any issue with it. It’s primarily the boats that get used one to two times a month,” Petersen said.
Ethanol fueling problems appear to be on the rise across the country. Boating Industry magazine recently asked dealerships, marinas, and engine and boat manufacturers about ethanol issues, and 87 percent of respondents reported seeing boat engine damage caused by ethanol — a 73 percent increase over the previous year.
“Dealers, manufacturers and marinas are clearly very concerned about the increased use of ethanol,” Jonathan Sweet, Boating Industry editor-in-chief, said in a statement issued by BoatUS. “According to our readers, ethanol is playing an increasing role in causing engine damage and other repair issues.”
Ethanol is essentially alcohol made from corn and other products. It has been added to U.S. gasoline for more than a decade, and nearly half of U.S. states have E15 ethanol blends at the local gas pumps. In New England and New York, the blend is 10 percent, which is the maximum allowed in many small engines, including marine motors.
However, a recent Harris Poll found most people don’t pay attention to the fuel they use, suggesting these higher blends are finding their way into marine engines.
What exactly is the problem with ethanol, and how does it affect an engine?
“The alcohol grabs the moisture and combines into a water solution that’s heavier than fuel, so it sinks to the bottom where it is closer to the pick-up for fuel,” Petersen said. “It will start to run poorly for a little bit and if enough gets into the carburetor it will stop working completely.”
There are alternatives. Some marinas and fueling stations still offer ethanol-free fuel; others such as Maine Yacht Center in Portland, Maine, use additives to make the E10 ethanol gas more stable.
Many auto parts stores sell one-quart cans of ethanol-free fuel that can be used in small outboard motors, said Brian Harris, general manager of Maine Yacht Center. He also recommends using aviation fuels, which do not contain ethanol.
“But it is not an economical solution if you are using a lot,” Harris said.
Petersen recommended a solution to help minimize fuel problems: keeping the fuel vent cap closed stops the ethanol from pulling moisture from the air.
However, he recommends boaters open the vent cap once or twice a week to release pressure.
“Only 100 percent way [to avoid issues] is to use the fuels we had 10 years ago with zero ethanol,” he said. “But customers … that are keeping the vent cap closed have had pretty good luck with it.”