1. Check the choke. Make sure the choke is fully engaged when you start the engine. The choke is a device that restricts airflow to the engine, which helps to create a richer fuel mixture that is easier to ignite in cold weather.
2. Check the fuel system. Make sure there is enough fuel in the tank and that the fuel lines are not kinked or blocked. You should also check the fuel filter to make sure it is clean and free of debris.
3. Check the spark plug. Make sure the spark plug is properly gapped and that the spark plug wire is properly connected. A weak or faulty spark plug can make it difficult for the engine to start in cold weather.
4. Check the battery. Make sure the battery is fully charged and that the battery terminals are clean and free of corrosion. A weak battery can make it difficult for the engine to turn over in cold weather.
5. Check the air filter. Make sure the air filter is clean and free of debris. A dirty air filter can restrict airflow to the engine, which can make it difficult to start.
If you have checked all of these things and the engine still does not start, you may need to take it to a qualified mechanic for further diagnosis.