I am trying to diagnose the proper operation of my son's Kasea 50 electric choke. Cold starts (after several days) are difficult. What I know is that 12v is applied to a heating (I think) element which causes movement of a needle - either to seal or open a port - causing a "choke" or "no choke" condition. What I am trying to find out is what is the principle here. Is the needle normally (cold) seated or open? And what is going on - does this port cause more fuel to be admitted, or does it choke airflow? Does anyone understand the proper operation of this unit?