The threaded flare port on the choke housing is used for warming the choke from an exhaust heat stove, a metal line would run from that port to an exhaust heated coil of tubing. You need to cap that port with a flare cap since you have an electric choke, (like a 75 Johnson, electric choke). Also, if there are any other open nipples or ports on the carburetor, those need to be capped. The adjustment screw under the choke is a fast idle adjustment, it works in conjunction with the choke, when the choke is automatically fully closed, that screw will be on the highest step of the fast idle cam, as the choke warms up, the cam drops down to progressively slower steps, If the engine is way too fast or blowing black smoke on a cold start-up, you need to adjust the fast idle screw. Are you running with 2 PCV valves? one of those PCV hoses should have a PCV valve, the other hose should be connected to filtered air with no valve in the rocker cover.
The fast idle cam does not work. Maybe it’s not adjusted right? My VW works like that one. It keeps the motor running faster until it warms up and I press the throat to release it.
