Without the regulator the battery is getting blasted with voltage. Will it run with the lights on high beam or some other power load? Check the voltage at your battery with the engine running. If your voltage is greater than 15.5 volts, your voltage regulator is bad. I've been told that will cause the crappy running (idles great, but won't run!) as I am in the same situation as we speak. My voltage is at 18.7 volts! I have ordered a regulator and should be in by Thursday. Since no one seemed to have an answer to my question on the AC forum, I had to ask a lot other folks and call the nearest AC shop. They said too much voltage (IE:a bad regulator) would cause that so I guess I'll see soon. Also, if you regulator is bad and your volts are too high, it can cause other damage to your electrical system so you may want to check it out.

 

By the way.....

New rectifier/regulator fixed mine right up! Been riding everyday since repaired Saturday morning.