You may not want to hear this but these guys have given every bit of info that it takes to make any engine run. If it is properly timed, getting spark and good gas it has to run. It has to be either a bad replacement part or bad fuel. I think you have to go back and look at everything again. I had a problem with an engine running fine until you dropped it in gear. I changed the converter, carb and distributor and still had the same problem. It turn out that the electric choke wire was connected to the power for the coil, reducing voltage just enough to give me fits. Maybe yours will be something as simple as that.