Friday, April 17, 2009
Ethanol can cause problems with boat motors
Today's gasoline, much of which contains 10 percent refined alcohol, can cause problems with boat motors.
Mark Taylor
Mark Taylor's Outdoors column and notebook appears regularly in The Roanoke Times.
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Being the head of Virginia's freshwater program doesn't mean you're immune to issues affecting the state's everyday anglers.
An issue, for example, like a motor that won't run when you're 7 miles from the nearest boat ramp on the James River.
In this case, Gary Martel wasn't on board. His son, Andy, had the boat for a day of duck hunting. "I didn't have another boat so I couldn't go get him," Martel said. "He was stuck out there for nine hours until one of his friends got off work and could go get him."
The problem?
A fouled carburetor.
The real culprit?
Gasoline that contained ethanol.
"The [fuel line] squeeze ball had deteriorated on account of ethanol and gummed up my carburetor," said Martel, whose bill for the repair job on the 25-horsepower engine was over $600.
Fuel containing ethanol is causing headaches for many boaters for a variety of reasons. Among other things, ethanol is a solvent that can degrade elements within the fuel system, it may have a shorter effective life span than regular gas, and it bonds with water molecules better than gasoline, which eventually can pull water into a fuel system.
While the issues, which can lead to expensive repairs, might be unavoidable, they can be addressed through a variety of basic maintenance steps, including using fuel additives.
At Smith Mountain Boat and Tackle in Penhook, owner Scott Reynolds said he has seen ethanol-related issues increase recently.
"It's gotten worse the past few years," Reynolds said.
At his work bench, shop mechanic Shawn Murphy pointed at mustard-yellow stains on a paper towel.
"That came from the inside of a carburetor," he said.
While gummed up carburetors are nothing new, that color is.
"It's like a green bacteria," Reynolds said.
Bob Brown, a technical service representative for Bombardier Recreational Products has a name for it.
"I call it skin," he said.
As a solvent, ethanol can clean varnish build-up and surface corrosion from fuel systems. If those particles exceed the system's filtration capabilities, engine performance will suffer.
The growing proliferation of four-stroke engines has likely exacerbated such problems because orifices in those motors' fuel systems can be smaller, thus easier to clog, than those in two-stroke systems.
Ethanol also increases problems with water getting into a fuel system.
A refined alcohol, usually made from corn, ethanol is hygroscopic, meaning it has a strong attraction to moisture.
It's difficult, if not impossible, to keep water out of a boat's open fuel system. Water can weaken the bond between gasoline molecules and ethanol molecules, and the ethanol molecules can attach to water molecules in a process called phase separation.
The ethanol/water mix will settle at the bottom of the tank, from which fuel is drawn.
If an engine can run on the ethanol/water mix, it will likely not run well.
The easiest way of dealing with ethanol-related boat motor issues is to use gas that doesn't include ethanol. But such fuel is difficult, if not impossible to find these days.
That leaves boaters trying to minimize the impact.
Brown said there are many suggestions.
"You can talk to 10 different people and get 12 different answers on what to do," said Brown.
Importantly, never use fuel that contains more than 10 percent ethanol.
A smart first step is to use a fuel stabilizer, which can prolong the life span of fuel with ethanol.
Completely draining a fuel tank can help because it will remove existing water from a tank. According to a Yamaha service manual, a 25-gallon gas tank that has 16 ounces of water can eventually lead to phase separation which could create nearly 3 gallons of ethanol/water mixture in the tank.
Empty fuel tanks should be mechanically cleaned to remove deposits and corrosion. Older tanks may need to be replaced.
Once fuel tanks have been cleaned, keeping them nearly full can help reduce water absorption by minimizing air space. After use, carburetors should be drained.
Installing a 10-micron fuel filter, and frequently replacing the filter, can help keep water and deposits from reaching the engine.
Being proactive won't eliminate all potential problems, but it will help. For boaters who have spent hours stranded with a dead engine, that's better than nothing.
