Owners manual does not address this. I am used to manual chokes as found on classic cars/hot rods. Butterfly that restricts airflow thus making it richer that is adjustable from completely closed to completely open. I know the bings dont use butterflies, its fuel passengers. Then realized that this may not be an adjustable setup. Are these only 3 positions (off, mid, all on choke) or are they graduatingly adjustable (is that a word)? Does my question make sense? Not sure i am describing it very well.