Thanks for your question. I will do the best that I can to help you.
It could be the spark plug wires or the distributor cap or the rotor. It also could be the ignition coil. There is a chance it could be the carburetor too and there is an outside chance that it could be the ignition module or the distributor itself.
I would recomend to start changing the cap, rotor and wires. We need to eliminate this and it won't cost too much as it is necessary maintenance anyway. After this, see how it runs.
If it still does it, then I would recomend taking a small propane tank and hook a hose to it and stick it into the carb while the engine is running. This will enrichen the mixture and if it is running lean, it will start running better with the propane.
Let me know how you make out and I will keep helping you until we get this solved.
If it was the carburetor, it would have to be either too rich or too lean. If it was too rich, you would see gas dripping down inside the carburetor while it was running and doing the problem. Take the air filter off and get yourself in a position to look straight down the carburetor and see if you notice any gas dripping down. At idle, there should be no gas dripping down at all.
If it is too lean, then if you add propane to the carb, it will run better. If you suspect the carb to be the problem, do these tests so we can get some kind of direction.