/6 wont start/ run with choke

Is this a carter BBS single barrel carb,???. If so the float level might be off. It should be set at 1/4 inch. You have to take it apart to adjust it. It is at the fuel intake, in back of the fitting. You must take the fuel fitting out to set it. Slightly bend the little tab that contacts the back of the needle, very gently, one way, or the other, to get 1/4inch. The needle faces the inlet (back) side of theinlet fitting. After 1/4 inch is obtained, set the choke idle,, and fast (curb) idle.
The choke idle screw should be set to about 1/4inch measured form the back of the acellorator plate. The fast idle screw should be se to1/2 inch, measured on the back.Choke idle screw is the inboard, screw, fast idle screw is outboard screw. Screwe settings are approximate. THis should get it running to where you can adjust it.
Set idle mixture screw (on carb base) about 2 turns out from full in. Do it very gently.

Dave