The engine on a Homelite weed eater operates through an internal combustion engine. For these engines to continue running with full power, they need a constant supply of gas, air and spark. When any of these three components falls out of balance, the engine won't stay running and will die.
Gas Supply Cut
A majority of engine problems on a Homelite weed eater occur in the fuel system. Whenever old or bad gas was used or left in the engine, it will stick to the fuel system parts and cause havoc for the flow of fuel. This restriction, even if it's small, will create a deficiency in fuel and shut down the engine. A thorough inspection and cleaning of the fuel system might be required to get the engine running at full power again. Drain all the fuel in the tank, and clean it with a brush and a rag. Pull out the fuel filter and fuel hoses if you suspect them of being clogged.
Air Supply Cut
For the fuel to ignite inside the cylinder, it needs to first get mixed with the right amount of air. If the fuel can't mix with the right amount of air, the fuel mixture will be wrong, and the engine won't stay running. The air filter on Homelite weed eaters needs regular cleaning, usually after every eight to 10 hours of operation. Wash the filter in soapy water and rinse it under cool water. Let it sit out overnight to dry thoroughly. Replace the air filter if it can't be cleaned.
Loss of Spark
The spark plug must deliver a high enough charge of electricity to ignite the fuel at the right temperature to keep the piston and crankcase moving. The loss of this charge will interrupt and stop the combustion process, shutting down the engine. Unhook the rubber boot from the end of the spark plug, and remove the spark plug from the cylinder. Check the tip of the spark plug to make sure it isn't oxidized or fouled. Replace the spark plug at least once a season.
Other Possible Issues
While these elements cover the basics of engine problems, a wide variety of other problems may be occurring inside the engine. However, usually these problems relate back to a loss of fuel, air or spark. Other problems can occur with dirty carburetors, dirty exhaust systems, bad ignition timing and air leaks inside the engine. These problems generally require a substantial knowledge of small engine repair. For this reason, these repairs are better left to a professional.