Rough idle on cold start ?

[geezer#99]

First thing I’d try is adjusting the black cap. It might have a lean/rich indicator on the cap.
Loosen the three screws holding it on and rotate the cap a bit towards the lean side. It might not take much.
If no marking on the cap then just hold the throttle open slightly and rotate the cap and watch the choke blade. It’ll be easy to see which way to turn it to make it leaner.
You won’t need to make much of an adjustment.