Carburetor needle & seat kit. Comes with installation instructions. The float needle allows fuel to enter the float bowl. If the float needle is stuck closed, the engine will not get fuel and thus will not start.
Genuine OEM Part - Manufacturer #398188
Carburetor fuel inlet needle. This needle can get stuck if fuel if left inside the carburetor for extended periods of time. Ethanol in the gasoline can cause it to turn into a varnish-like substance and cause the engine to not start.
Genuine OEM Part - Manufacturer #231855S