Solex 4A1 Carburetor on W123 280 (1981)

Slex 4A1 Carburetor on a Mercedes W123 280 (1981) The car starts fine when engine is cold, but as soon temp. gets to 85°c. the car starts shaking till rpm goes down and offently will turn off. I think the problem is related with that metal arm connected to the choke system or the thermal actuator, if anyone has an idea of what might it be i appreciate any kind of help.