Verify you're getting power to the coil, then spark from the coil, then spark from the distributor cap. Also, lean over the carb, with the air cleaner off and the key off, and work the throttle on the side of the carb, you should be able to see the jets spray fuel as you turn the throttle back and forth. Before you go throwing parts at something, always remember that an engine takes 3 things to run....air, fuel and spark. That is the easiest place to begin, in terms of troubleshooting.