My 2002 buell blast is not charging what could be some possible problems

First thing to check is your regulator, start the bike and put a meter on the battery, you should see about 14volts. If the bike is not charging (12volts or less) unplug the wires going to the regulator and put the meter leads on the plug going into the regulator and set the meter to "Volts - AC" with the bike running the meter should read somewhere between 30 and 50 volts AC. If you see between 30 and 50 volts AC then its your regulator thats shot, if you don't see those numbers then your problem is most likely the Stator. Make sure you check for broken wires, short circuits etc before jumping in and spending money on expensive replacement parts.