You can usually tell if the carb is a major problem by using starting fluid. With a friend cranking the engine spray a little bit down the throat of the carb and work the throttle. If it runs off starting fluid but dies when you stop it's definitely fuel related.
If it doesn't run at all with the starting fluid test then it's spark/timing
Since starting fluid will take the oil off of the cylinder walls, I would recommend 1/2 a tablespoon of gas or so poured directly down the carb throat and then immediately start it. If it runs well for a few seconds, then it is a carb problem.
And not to dismiss any suggestions or knowledge, but you can't go wrong to follow the procedures laid out be 67Dart273.
