How to fix your Weed Eater gas walk-behind lawn mower when its engine runs rough
If your lawn mower cuts out, smokes, idles poorly, vibrates or runs erratically, it could need a good tune-up to replace the spark plug, oil and air filter. Or the problem could be with the lawn mower's fuel system. Rebuild or replace the carburetor if the engine isn't getting a good supply of fuel.
If the engine misfires, backfires, sputters or jerks the starter rope out of your hand when you try to start it, the flywheel key could be broken. A broken flywheel key disrupts the ignition timing because the magnets aren't passing the ignition coil in synchronization with piston movement. Replace the flywheel key if it's damaged or broken.
What to do when your Weed Eater gas walk-behind mower vibrates too much
When your mower vibrates severely, start by checking whether the blade is damaged, imbalanced or loose. Tighten the blade bolt if it's loose. Replace the blade if it's damaged.
A rough-running engine can also cause severe vibrations so tune up the mower to cure engine vibrations.
If you have a hard time pulling the starter rope and the engine sputters when starting your lawn mower, the flywheel key might be damaged.
