Activated by the choke linkage

[piero]

Sorry but I don't know their names but...they are activated by the choke lever and they show in the attached picture by a red arrow pointing at them. They are located in the rear of the carburetor bank, they have a black cover that in the one to the right of the picture the "cover is missing". I have that cover as a spare even if I'm unable to tell you how I was able...to order it. The problem is that I have no idea how that cover stays, or click on its base. It's a mystery to me because the other one (left side of picture) stays put and does not come out. Now, do I have to glue that black cap on top of its base or do you have a suggestion?

By the way, by clicking on the picture you....will expand it!

Thank you - Piero Bassi