Ok I'm new here. I have a 03 Duece. The problem is misfiring at constant speeds. At first, I thought I had gotten some bad gas so I drained the tank and filled it with fresh gas. But, no change. I have tried new plugs, and tried different plug wires off of a friends Duece. But, the problem is still there. I can roll the throttle and it runs like a champ. At constant speeds there is still a misfire. I need some input on this problem.