[Masteryota]

First question, you say it has spark. What color is the spark? Orange is not good, a thick blue arc is what you want. Under heat and compression, the orange spark is not hot enough to ignite the fuel mix. Make sure to check all the connections on the coil and CDI, I have heard of some spade terminals being loose enough to break connection.

The next thing I would check is the compression. Compression gauges are relatively inexpensive at harbor freight. Honestly, I would check the valve adjustment first. Pulling the valve cover off is pretty easy, and all you need is a decent set of feeler gauges, available at sears, harbor freight, etc. If the valves are too tight, it means the valves are being held open when they are not supposed to be and allowing the fuel and air to escape before it can be ignited.