1. The engine cannot start. Cause: No gasoline; spark plug wire is disconnected; throttle switch is not in starting position; oil path is not open; ignition is misaligned; spark plug is damaged. Remedy: Add gasoline; connect the spark plug wire; turn the throttle switch to maximum; clean the oil circuit; correct the ignition time; replace the new spark plug.
2. The engine is not running smoothly. Causes: The throttle is in the maximum position, the damper is in the open state; the spark plug is loose; the water and dirt enter the fuel system; the air filter is dirty; the carburetor is improperly adjusted; the engine fixing pin is loose; the engine crankshaft is bent. Remedy: Lower the throttle switch; secure the outside of the spark plug; clean the fuel tank, refill with clean fuel; clean the air filter or replace the filter element; readjust the carburetor; check the engine mounting dowel after flameout; correct the crankshaft or replace the new shaft.
3. The engine cannot be turned off. Cause: The throttle cable is improperly installed on the engine; the throttle line is broken; the throttle is not sensitive; the flameout line cannot be touched. Remedy: Reinstall the throttle cable; replace the throttle cable with a new one; place a small amount of oil on the active throttle position; check or replace the flameout line.
4. Drain the grass poorly. Causes: Engine speed is too low; grasses block grass; grassland humidity is too high; grass is too long and too dense; blades are not sharp. Remedy: Remove grass from the lawnmower; have water on the lawn and wait until it is dry before cutting; divide it twice or three times, cutting only 1/3 of the length of grass at a time; sharpen the blade.
