This is normal for the Carter YF & YFA. The metering rod does not fit tight. It is built to restrict a certain amount of fuel, not to shut if off.

Carburetor runs rich at idle.

Among other things check the idle tube to make sure it is clear. Run thin wire down the hole to clear out any ethanol residue. See number 42 in the illustration.

Whilst following your adjustment instructions and when carrying out the metering rod adjustment,can you tell me if I should disconnect the link pump connector first.

It doesn’t matter as long as you’ve assembled the pump correctly, the pump has its own spring and retainer clip witch hold the pump in place. The metering rod has its own spring and clip witch hold it in its own place, your adjustment is that part only. Hope this makes sense.