This weekend, I experienced a recurrent problem, this time in spades. The car, after being warmed up does well in first gear, but after shifting into scond, I get the stumble and backfire through the carbs and then all seems smooth. The smooth running gets rough when the car hits 180 degrees, and it sounds like I am running on three to four cylinders. When I press the excellerator hard, I do not get any appreciable increase in engine speed, but a lot of noise and popping. My first inclination is a carb issue; however the rule of thumb is check everything else before touching the carbs. I do not thik timing is the issue, since the car starts well and runs cool. Any ideas?