How to Troubleshoot a Weed Eater 300 Series

Move the Weed Eater 300 onto a level piece of ground to perform these troubleshooting tests. Make sure the lawn mower has plenty of gas and oil.

Unhook the rubber boot on the end of the spark plug. Unscrew and remove the spark plug from the engine using the socket wrench and spark plug socket. Replace the mower's spark plug if the electrode tip looks black, bent or broken.

Screw the new spark plug into the cylinder hole. Connect an ignition tester to the rubber boot and the tip of the spark plug. Pull hard on the starter rope several times. Watch the ignition tester's window for a blue spark. Repair the ignition system if there's no spark or it's a weak yellow.

Take the ignition tester off the rubber boot and spark plug. Remove the spark plug from the cylinder again. Connect the compression gauge to the spark plug hole and tighten it down with your fingers.

Pull hard on the starter rope again until the compression needle reaches its maximum point. Check the reading. Repair the compression system if the reading is below 90 psi.

Unscrew the air filter box and remove it from the side of the 300's engine. Disconnect the two rubber hoses from the carburetor with your fingers. Lean the engine over slightly to the gas side. Watch for fuel to come out of the gas hoses. Repair the fuel system if no gas comes out of the hoses.