This motor ran flawlessly smooth before. Now that I have it advertised for sale, I went and fired it up and it runs smooth and fine, then all of a sudden it misses and acts like it's starving for fuel. I can keep it running if I keep pumping the throttle (if I just hold it down though it sounds like its sucking air and just dies), so I have to keep on and off the pedal to keep it running. Then when it decides to, it runs and idles fine again. I'm thinking it's not a spark issue, but more of a fuel issue. It ran out of gas a week ago in the driveway, and maybe it sucked some sediment/particles from the tank into the carb. It's sat for about a week since it last ran fine.