I'm assuming that after replacing the points and plugs you verified that you are getting a spark. If that is true then it sounds like a fuel problem. You have rebuilt the carburator so the jets and float are clean. Here's what I would try. Get a can of starter fluid and spray it into the flame arrestor, (or remove the flame arrestor and spray it right into the carb,) and then try starting it again. My thoughts are that since you rebuilt the carb it is dry and it isn't pulling fuel into itself, and it won't until it starts. The starting fluid will give the engine something to fire on until the carb is primed. Also, this might be a stupid question, but is the fuel petcock turned to the on position at the fuel tank?? It's an easy thing to overlook. If the engine fires with the starter fluid but won't begin burning fuel on it's own you might want to take a look at the fuel pump. Keep in mind that I'm not a mechanic and that I'm only posting these suggestions based on my own experience as an Atomic 4 owner for a dozen years. Good luck!!