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Encounters With Ethanol Page 2


Paul Jennings was boatless for nearly three seasons after losing his vessel's port motor.

Jennings' wish was to take his beloved Stolen Moments, a late-1960's 34-foot Hatteras, and refit her with diesels. When he was ready to retire he was going to run her down to his second home in Florida. Like most boaters, Jennings was unaware of potential problems when on-the-water fuel in New York was switched from MTBE gasoline to the E10 blend. He'd spent years upgrading systems on the boat with his own hands, replacing the cockpit sole, and even doing an engine rebuild on the big-block Chrysler inboards.

But shortly after E10 was introduced into the New York area, Jennings found out in an intimate fashion the damage this greener ethanol could cause to Stolen Moments' powerplants and fuel system. The boat's engine started to lag, spit, and stall.

"I figured out the whole process by trial and error," Jennings tells me as he describes that at the point his motors started acting up he hadn't heard of any ethanol problems in boats.

This do-it-yourselfer started by checking the regular suspects such as points and plugs, and he even performed a compression test. Eventually he pulled off the valve covers and noticed a bent push rod on the port motor. Since he happened to have spares, he made the repair and went out to test the boat. Everything ran fine—for one day.

Within 24 hours he was back to square one with the new push rod bent and a second one bent as well. It was time to get serious. Jennings pulled the heads off the port motor, and when he looked inside the intake manifold it looked like "someone had dunked it like a candy apple," he says, noting there was a sticky, gum-like substance all over it.


"When I looked down at the carburetor it looked fine," Jennings says, adding that when he viewed the underside of it there was a lacquer-like goo sticking to it. The valve stems were stuck, too. He then checked all the fuel lines and filters (each motor has three in-line units), and oddly they all looked fine. (Ethanol doesn't always show up in the fuel filters.) He was baffled.

After inquiring with friends, fellow boaters, and mechanics, he eventually suspected that the culprit could be ethanol. An inspection of his boat's integral fiberglass fuel tanks showed what he called "flakes" in the fuel (similar to the aforementioned owner's "chips"). Jennings says dryly, "Ethanol is a good solvent."

To keep his boating dream alive, he began working on a solution. First, he had the top end of his freshly rebuilt port motor rebuilt again. (The starboard motor wasn't as severely damaged so it did not need attention.)

In addition, he had the boat's new deck cut up so he could get at the fuel tanks. He removed them and ordered aluminum ones with increased capacity and moved them closer to centerline. Figuring he had the boat open anyway, Jennings also opened up the exhaust from four inches to six inches in preparation for his eventual move to diesel inboards.

Because he's handy, the repairs for his boat came in the few-thousand-dollar range, but he estimated that if he had to pay someone for labor and parts all the work could've cost him in the range of $7,000 to $9,000, maybe more. More important, he lost two-and-a-half seasons of boating while troubleshooting and correcting a problem he didn't invite, cause, or create.

A majority of the ethanol issues involving clogged filters and sputtering motors have reportedly been tackled. But whether you have a new or used boat, or are buying one, make sure you get the lowdown on tank construction, hose materials, and fuel usage. It could make the difference between spending your season on the bridge or in the bilge.

E10 Fuel Facts

BoatUs, an organization that does everything from providing marine insurance to lobbying on behalf of boaters, has performed extensive research on E10 fuel and its effect on boats' fuel systems. To date, BoatUs says it has 70 documented cases of failed fiberglass fuel tanks due to E10 fuel. Here are a few ethanol facts from BoatUs' Seaworthy magazine.

  • E10, a solvent that can clean gum and resin off fuel tank walls, can also clog fuel filters and shut down an engine
  • Many older fuel hoses are incompatible with ethanol
  • Ethanol is known to chemically react with fiberglass fuel tanks, which can cause them to deteriorate and eventually fail. When this happens, the engine can also be destroyed before the problem is discovered. Fiberglass tanks most likely to react were those built before the mid-1980's, but there are reports of much newer tanks being impacted
  • Ethanol attracts water and will "phase separate," or form two separate solutions in the gas tank, usually over a long period of time. Once this happens, the engine may not run and internal damage can occur. The problem cannot be corrected; the only solution is to drain the tank and refill with fresh gasoline
  • Fuel stabilizers do not prevent phase separation.

This article originally appeared in the January 2009 issue of Power & Motoryacht magazine.