* Fuel problems. Make sure that the fuel tank is full and that the fuel line is not clogged. You can also try adding a fuel stabilizer to the gas tank to help prevent the fuel from going bad.
* Electrical problems. Check the battery connections to make sure that they are tight and that the battery is not dead. You can also try using a multimeter to test the voltage of the battery.
* Spark plug problems. Make sure that the spark plug is properly installed and that the gap is set correctly. You can also try replacing the spark plug with a new one.
* Air filter problems. Check the air filter to make sure that it is clean and not clogged. You can also try replacing the air filter with a new one.
* Starter problems. If the starter is not working, you may need to replace it.
If you have tried all of these things and your riding lawn mower still does not start, you may need to take it to a professional for repair.
