One suggestion for this is:
Make a note of the carburetor model (I assume if it's the R11 1.4 it will be the Zenith IF 32). In any case, it's written on the carburetor itself and in the technical section of the car's maintenance manual.
With this information, go to an auto parts store and ask for a "CARBURETOR REPAIR KIT MOD...." (preferably the one that includes the accelerator pump diaphragm; it's the more expensive of the two, around 25 or 30 euros).
Then take an empty oil can and cut one side off, as if you were going to change the oil, to make a sort of mini-basin.
To remove the carburetor from the car:
Remove the air filter (and the housing, of course).
Disconnect the choke and throttle cables from the carburetor, as well as the fuel and water lines (be careful with the water because it will leak, so try to find a cap for the line before removing it).
Remove the bolts that attach the carburetor to the intake manifold, being careful not to drop any nuts or parts inside the manifold.
Remove the carburetor seat gaskets from the manifold and the plastic spacer between the carburetor and the intake manifold, if present (I'm not sure).
Once out of the car, place the carburetor in the empty can, fill it with solvent or disinfectant, disassemble the carburetor, and using a small brush, clean it thoroughly until it's spotless.
Be careful with the solvent because, in addition to being flammable, it's intoxicating; the fumes will get you drunk, so it's best to do this in a well-ventilated area.
After all this, reassemble the carburetor piece by piece, using new gaskets.
Finally, reinstall the carburetor in the car, following all the steps in reverse order.
NOTE: The car will be a little hard to start at first, but that's normal since the fuel tank is empty.
You should have the CO (carbon monoxide) adjustment done at a garage, although if you have a mechanic friend, you can do it at home by ear and by smelling the exhaust fumes.
I hope this helps.