The freedom of movement of the choke servo can be checked on the vehicle or on the removed carburetor. In the latter case, the carburetor must be placed in a horizontal position.
Move needle 1 of the idle air jet down. at the same time, the air damper valve 2 should close.
If this does not happen, disconnect the connecting rod 3 and check if the air damper servo moves freely. If stuck, replace the servo. When installing a new servo after connecting rod 3, pay attention to the position of the groove and the locking lug (shown by arrows in the photo) and drive lever 4 air damper.