Husqvarna fuel filter. If the fuel filter is clogged, it will restrict the flow of fuel to the carburetor. As a result, the engine may not start.
Foam air filter
Leaf blower carburetor. If the carburetor is clogged, the engine won't get enough fuel. As a result, the engine may not start or may run rough. The carburetor can often be cleaned or rebuilt, but sometimes it may need to be replaced.