Hello! Dear members of the forum, I am from Belarus and I very much like your car/
I found on the web site with lots of old and rare repair manuals from Mitsubishi Motors, including on CORDIA and TREDIA here is the link may be useful:
http://sigma.bplaced.net/werkstatt/
Everything is in German, but with the help of Google Translate can understand.
My car got me with several carburettors, which differ from each other and I'm not sure how the car were equipped from the factory.

I need help with information about AISAN carburetor for 4G37, which is mounted directly on your machine CORDIA 1800GSL. To this end, it is not necessary to remove the carburetor from the machine.
1) The diameters of the primary and secondary diffusers throttle. Their figures are cast from the top and you can see them, if you remove the air filter and clean up the edges a bit diffusers gasoline or other solvent. If the numbers do not will be found, it is possible to measure the diameter of the school dividers, then attach to the lineup. The accuracy required in the 1 mm. I have 22 at first diffuser chamber and 28 at a second.
With best wishes, thank.