Gas String Trimmer Ethanol Problem

Overheating

• An ethanol blend in gasoline burns hotter than regular gasoline, which may cause an air-cooled engine -- the type that are prevalent on string trimmers -- to overheat. An overheated engine eventually stops running as the piston and the combustion chamber expand. Although the engine may start again once it cools, irreparable damage may have occurred to the piston rings, the valves and the crank. In these cases, the engine or the entire trimmer must be replaced for proper use.

Water Absorbtion

• Ethanol attracts water, which if left in the gas tank or cylinder head for any length of time, causes rust and corrosion. This corroded coating begins to compromise the trimmer's engine performance, and as it gets worse, bits and pieces may break off and damage the internal combustion process by clogging up valves and fuel jets.

Plastic Part Deterioration

• Ethanol corrodes or warps plastic pieces and parts. Many fuel-related parts on a string trimmer are made of plastic. Once the plastic pieces exposed to ethanol become corroded or warped, the trimmer engine's performance may become severely compromised. Although these parts are repairable under most circumstances, it may be more cost effective to replace the trimmer with a new one.

Other Options

• The best cure for any ethanol-related problem is to use a non-ethanol mixed gasoline. Any gasoline labeled E10, E15 or E85 is detrimental to a string trimmer engine. Only gasoline that is not mixed with ethanol solves all of the problems. Non-ethanol mixed gasoline is available at most gasoline stations, but there also are boutique or premium gasoline blends, usually in quart containers, that are available at hardware or retail stores.