Your repairman is correct and so is your research. These ethanol fuels are not a problem if they are consumed quickly in the engine. The problem lies with all equipment that has a tendency to get unused for long periods and boats are also one of those items that get put into storage in the off-season.

For boat owners, this issue has been horrendous and often expensive. As I understand it, some boat owners have had to pay to have their tanks removed because there was no way to clean the bad fuel out of the tank. This meant cutting up the old tank that had been installed as the boat was being assembled but could not be removed due to the access hatch being too small.

On some of the older outdoor power equipment engines, carbureter floats were made from a foam material which performed just fine in pure gasoline but began to swell when in contact with gasoline containing ethanol. This swelling caused the float to jamb against the side of the floatbowl causing engine flooding or fuel starvation.

The current thinking is that these ethanol fuels should be consumed within 30 days of purchase to ensure no problems. I'm not aware of any fuel stabilizers available that will guarantee no problems but others are free to comment on this issue. You should purchase small quantities instead of filling a 5 gallon gas can like we used to do. After 30 days, dump whatever is in that gas can into your vehicle and burn it up.

Run your outdoor power equipment until the engine uses up all the fuel in the tank when storing the item for winter. You can use a turkey baster to remove the greater amount of fuel from most tanks and squirt that fuel into a gas can. It is unwise to do this procedure indoors or while smoking your pipe, cigar, cigarillo or cigarette.

STA-BIL 22240 Marine Fuel Stabilizer - 32 oz.

Product Description
Gold Eagle Marine STA-BIL Fuel Stabilizer is the best ethanol problem fighter. This is more than four times the fuel system cleaner than the regular STA-BIL and double the corrosion fighter. Marine STA-BIL prevents corrosion from moisture and ethanol-induced water attraction. If you are using ethanol blended fuel in your marine application, Gold Eagle recommends Marine STA-BIL with EVERY fill up, not just for storage. This 10 ounce quick measure easy pour bottle treats up to 100 gallons of fuel.

STA-BIL 22214 Fuel Stabilizer - 32 Fl oz.

Product Description
Gold Eagle STA-BIL Fuel Stabilizer keeps fuel fresh for quick easy starts after storage. It removes water to prevent corrosion and cleanses carburetors and fuel injectors. This product also protects engine from gum, varnish, rust and corrosion and prolongs the life of any engine. Eliminate the need to drain the fuel of your 2 or 4 cycle engine by treating the fuel with STA-BIL before storing. This 4 ounce quick measure easy pour bottle treats up to 10 gallons of fuel.

Yes most gas have ethanol and has to be used in 30 days. I use Marine StaBil ( blue color) and I still would not keep it over 4 months. Supposing good for a year but I won't push it.

Water absorbed by ethanol is the major cause of problem. These gas turn bad, turn into gum and block the passage inside of the carb.

SeaFoam is very good in cleaning gum out of the carb if you can still start it. Use regularly to keep everything clean.

New equipments should have design to use gas with alcohol, the old equipments are a different story.

Thank you all for your responses. Kompressor for confirming what I had learned, Loger for the info on stabilizers, and Yungman for the info on storage.
I evidently missed the memo, email, letter, news, whatever that came out about the ethanol in gas and the potential problems. :)
Lessons learned:
1 -purchase only small amount(1 gal) of gas at a time. Use quickly within 30 days or discard.
2 - get it out of weedeater asap when the weed season ends or when I am not going to use weedeater within 30 days or less.
Thank goodness I learned all this with a weedeater not a boat!!
Murphy

I personally use fuel with Sta-Bil up to a year without draining any fuel (boat, lawn mowers, blowers, trimmers and chain saws). This is at last 3 years w/o any problems. Plus, I feel many boaters and others have changed their philosophy on storing boats etc.. Such as, leave the fuel in with Sta-Bil, "mainly an additive to counter EthanolÂs moisture and deteriorating effects" and you will have better internal protection, "Off Season". loger

Just below this thread is a long thread on Weedeater's Featherlite trimmers and ethanol that are interesting. loger

Ethanol Fuel in small engines a problem???
Âh Posted by: murphy_zone7 on Fri, Jul 23, 10 at 7:29
ÂÃ 5 follow-ups, last one posted on Sun, Jul 25, 10 at 15:38

Featherlite weedeater
Âh Posted by: hut123 on Sun, May 15, 05 at 17:16
ÂÃ 27 follow-ups, last one posted on Sun, Jul 25, 10 at 10:42

The gasoline and alcohol do not react so there are no reaction products that can contaminate the gasoline it. can absorb more water than gasoline without it, When the concentration of water reaches a point, a precipitant will form that is a mixture of Water, alcohol, and gasoline. This precipitate can hinder the flow of gasoline.

For 2 cycle engine you now have a solution with four components, alcohol, oil, gasoline, and water. The stability of this solution is less than that of the three component fuel for the 4 cycle engine. Since you have four components in the solution the point where all four components are soluble, it will take less water to start the separation. This precipitate will clog the system.

You can do things to minimize the absorption of the water. Keep the gas in tightly sealed containers. The container should have, a valve that limits the incoming air. If you have a container that can handle the expansion of the air in the container this should not be a problem. By limiting the incoming air you limit the possible water that can be adsorbed into the gasoline.

There is a another thing that will affect these solutions. That is temperature. As the temperature goes up the stability of the solutions goes up and they can contain more water. By keeping the gasoline away from freezing temperatures, they will more likely remain one solution with no precipitation. d trying to heat the gasoline to re dissolved the precipitants.
********** NOTE: I would not recommend trying to heat the gasoline to re dissolved the precipitants. **********

In a tightly sealed container kept at relatively warm temperatures, you should have no problem in storing the gasoline over the winter.

If the small engine has a fuel shut-off valve, it is possible to close the valve, with the engine running, and get most of the fuel out of the carburetor. This can be done at the end of every session, and it will greatly reduce the need for carburetor maintenance. If there is no fuel shut-off valve, you can achieve the same result by partially filling the fuel tank, and running the engine dry, until it stops. This will take some extra planning, and result in having to finish the job by hand, if the weedeater stops a minute too soon. However, the effort pays off in easy, reliable start-ups.