To adjust the choke, loosen the 3 screws and take the choke spring and turn it until the choke plate closes. Push the pedal to the floor once, the plate should open slighty. then start the truck - it should be on the first step of the cam - tap the pedal, it should step down to fast idle - adjust fast idle screw to 1400 to 1600 rpm. The carb will step down to regular idle as the choke warms up - if it drops too fast to curb idle, increase the spring tension on the choke.