hi, first the gap should be .060 ,they found on these year motors that the .080 was too much of a gap and said it should be .060 instead .
this sounds to me to be a carb issue .
has anyone tried to adjust the air/gas mixture screws ?
other issues with this carb is that the metering rods in the carb are electronically controlled and the fuse would blow out sometimes -
this in turn make the car run rough and stall and sometime hard to start .-so check the fuses in the inside fuse box.
also,if the air/gas mixture screws are not adjusted right that too will causes rough idling and stalling .
and when it's idling look down inside the carb and see if you can see gas dribbling -that is a sign of dirt in the carb/ or air/gas mixture is off adjustment
the air/gas mixture screws on the carb were sealed and the seals have to be removed to get at the screws .
this involves taking the carb off ...jazzmaster .
let me know if it dribbles gas inside the carb at idle ..thank you