Faulty fuel mixture can be:
no two-stroke oil in the fuel
too old fuel
wrong fuel type
wrong ratio between fuel and two-stroke oil
1.Remove the muffler cover, then remove the spark arrester screen located at the front of the muffler beneath the cover.
2. Inspect the spark arrester screen for damage. Ensure it is free from tears or holes and check for excessive carbon buildup. A clogged spark arrester can restrict exhaust flow, reducing engine speed and performance.
3.Remove any carbon deposits using a wire brush. Once the screen is clean, reinstall the spark arrester and refit the muffler cover.
Husqvarna recommends cleaning the spark arrester screen every 50 hours of operation.