On a VAZ-2121 car with a carburetor engine, three filter elements of the fuel system are installed, in addition to the fuel inlet mesh of the tank
These elements include a fine filter, a carburetor filter, and a fuel pump strainer.
Replacing the fine fuel filter

Use a Phillips screwdriver to loosen the clamps on the gas hoses

Remove the fuel filter
We install the new filter so that the arrow on the housing points to the fuel pump.
Attach the gas hose clamps.
Removing the carburetor fuel filter

Remove the air filter housing.

Use a Phillips screwdriver to loosen the fuel supply hose clamp

Remove the hose from the fitting.

Use a 13 key to unscrew the fuel supply fitting

Take it out together with the copper sealing ring

Take out the fuel filter, wash it in clean gasoline and blow it out
Cleaning the fuel pump strainer
You can clean (replace) the strainer without removing the pump from the engine (for clarity, the operation is shown with the pump removed).

Use a 10mm wrench to unscrew the bolt securing the pump cover

Remove the cover and take out the mesh filter