The factory settings seem to vary from 3/4 to 1 3/4 turns. To meet world wide emission requirements, this is as lean as they can be set and still run OK.
The inner snorkles may not be there, this seems to be a regional market thing with them installed as required to meet local noise limits.
It is best to adjust the idle mixture to where you get the highest idle speed. When mine were adjusted to eliminate exhaust popping completely, it cost me some 10 - 15 MPH at the top end because the idle and transition jets start functioning again as a high speed power enrichment circuit.
