If starting fluid doesn't even get it to try to start your problem is probably electrical (ignition). Either pull a plug wire off and insert a phillips screwdriver into the plug socket and hold it near the engine block while someone cranks it (HOLD THE INSULATED PART OF THE SCREWDRIVER OR YOU WILL GET KNOCKED ON YOUR CAN) or buy one of the $ 5 spark plug testers that light up when that plug fires to let you know you are getting spark.

If it ran ok during breakin something changed. Start with the basics. Also, look at the plugs to make sure you aren't flooding.

Don