First thing I would do is pick up a shop manual. It will tell how to test every part of the charging system using an ohm meter. You're right about the 14 volts while running. Speed the engine up to 2000 rpm and see if the voltage goes up to around 14 to 16 volts. If it don't go up at 2 grand then it's not charging.Most bikes don't charge at idle. How old is the battery? If the battery is old and shot it might not take a charge or let the charging system do it's job. The charging system needs to have somethin' to go off of and if the battery can't take a charge it won't give it a charge.