Hi, well? if the carb is old it may just be very dirty in the float bowl. i think that the fuel filter should be changed and that the fuel pump checked to see that it is working ok. check the fuel line in the trunk to see that it is not kinked or pinched. if you had the rear seat out it may have been installed incorrectly and is cutting off the fuel supply. old hoses are also a problem because the pump my suck in air bubbles occasionally. as for running good and bad i think that the choke out displays that a lean run condition exists at that time, this is when the stuff in the float bowl probably is in the primary fuel circuit. best shot at a repair remove the carb, dismantle completely and reassemble. good luck, post or e-mail your results. stone stone racing co. phila pa 215.592.0265