Key point to remember with 'Bleeder Carbs' as described by Mr67stang, is that the adjustment screw works opposite of all the conventional double needle types.

To Make the midrange mixture leaner you back that screw out. To make the midrange richer you screw it in.

An easy starting point that works well with all the FP series Bleeders as well as the LA series carbs is to insert a heavy pin or large safety pin opened up into that hole in the front with that horizontal screw backed out. Now screw in that horizontal screw untill it starts to pinch the pin but you can still pull the pin out. Thats a good starting point for the midrange.

John