1 other thing to ask, what spark plugs are you using?
I had ‘black plugs’ and assumed that the carb was running rich but a colortune test said different, so I fitted some ‘hotter’ plugs which did improve things.
I have since changed again to EYQUEM N 43 F3+1 and the car starts and runs much better.
Also make sure that the engine is run up to temperature before checking the plugs colour.