To keep your string trimmer in top operating condition, follow these guidelines:
Never adjust the carburetor on a gasoline-powered trimmer. The carburetor is designed to mix air and gas/oil mixture in the right proportions for most efficient combustion. Improper adjustments can ruin the engine. Have the unit serviced.
Regularly replace the air filter and spark plug of a gas engine according to the manufacturer’s recommendations.
Before storing a gas engine trimmer for the season, run it until the fuel tank is empty or add a fuel stabilizer additive to the tank.
Keep gas and electric motors clean of dirt, dust, and plant debris.