Technical Engine question

[Paidparking]

Hello,
I have a few beginner questions about my 1978 fiat 1800. After timing done at shop, new radiator, new electric ignition, my fiat would idle super low when the engine was warm and sputter out. Thise was months ago, I have since moved and havent driven it again but ran it. I removed the air filter and housing from the carb, and now it idles low when warm but didnt sputter out. Is this normal? Could it be a fuel/air problem? I am attaching a video to help out, thank you!

 

[s130]

I've never worked on a 124 but looking at your picture the carb looks like it has an idle fuel cut-off solenoid. (the little round cylinder with two wires going to it). Normally I think this should only be activated during overrun conditions. If this a being incorrectly activated then the idle fuel supply is being restricted. Temperature is also probably one of the factors governing this operation.

It could also be that the idle speed throttle plate setting is too low.