A leaf blower is designed to blow air. With that in mind, you can appreciate how important it is to have a clean air filter. Remove the air filter cover, inspect and clean, or replace.
02 - Spark plug
Remove the spark plug and check if it is damaged or corroded. At this point, you can clean or replace it. If you have a spark plug tester, you can use it to quickly determine if your plug is in working order.
03 - Fuel filter
Remove the gas cap and use a pair of needle-nose pliers to pull the gas filter out of the gas tank. You can clean it with an air compressor or soapy water. If it is damaged, you should replace it with a new one.
04 - Impeller
The impeller is what creates the airflow in the leaf blower. Unscrew the cover and pull it apart. Inspect the impeller for damage or obstructions, and replace if necessary.