Ethanol may not be the answer
I really can't compliment the readers of this column enough. Their questions and comments are constant sources of inspiration.
For instance, reader and boater Bob Stengle recently pointed out that it has been reported that using ethanol-diluted gasoline should not have an impact on cars built after 1995, but those before may have problems with gaskets, seals and hoses.
"So what about boats?" he asked. "If this 1995 date applies to boats, we could have a big problem with most of our gas fleet. And what about the tank hoses hooked up to outboards? I would hate to be fishing on the Banks and start loosing hoses and have gas spilling into the bilge."
He went on to suggest that I might take a look at what impact our new ethanol requirements will have on the boating community, because, as he said, if ethanol is a problem, someone should raise a red warning flag before we have a casualty.
After a bit of on-line research, I found that a company in Australia did some testing of outboard engines with gasoline containing both 10 percent and 20 percent ethanol a couple of years ago.
The results of those tests seemed to indicate that while the 10 percent blend had negligible negative effects, engines using the 20 percent blend were observed to have increased misfiring, stalling and difficulty maintaining a constant engine speed.
It was also recommended in another Australian report that all plastic and rubber fuel system components should be inspected regularly for leaks and/or deterioration on older engines using ethanol blends.
In the U.S., the National Marine Manufacturers Association has found that engines using the 20 percent blend have elevated exhaust temperatures, cylinder pressures, and combustion deposits, along with burned head gaskets and exhaust valves after only 25 hours of light duty.
And finally, BoatU.S. -- a boat owner's association with more than 600,000 members -- had an article in its January magazine regarding the effects of ethanol on fiberglass fuel tanks.
"BoatU.S. has learned of more than 50 cases of fiberglass gas tanks -- many of them manufactured before the mid-1980s -- that produced an engine-killing sludge, or began leaking after being filled with 10 percent ethanol gasoline," it told its members.
It added that while the investigation is ongoing, it appears that ethanol, which was introduced in Long Island and other areas of the Northeast in late 2004, may be attacking the resins used in those tanks.
That degradation resulted in the creation of a tar-like substance that was not captured by fuel filters and it then created hard, black deposits that damaged intake valves and pushrods, and eventually destroyed the engine.
The article also confirmed reports of fuel tank wall failures, and to learn more, BoatU.S. has now commissioned laboratory experiments to determine the exact cause of the problem.
I promise to pass on the results of that testing as soon as they are available.