where is the air fuel adjuster screw on a vw golf 1.6 mk1 1989?

[darkavenger626]

I need to set the air fuel mixture on my golf but its a bit different to the old Datsun I used to drive obviously can anyone tell me where the screw is and what it looks like also which way do I turn the screw to make the mixture leener? a pic or video would be great but I cant find anything on google or youtube.