If you suspect your charging system, your best bet is to get an ammeter, preferrably a digital one because you can hook it up backwards and it will just have a negative sign before the digits. Analog meters will fry if you hook them up wrong. Even a cheap digital will work, just make sure it's rated for more than 27A which is the highest output of the alternator. Disconnect a battery lead and connect the ammeter between the disconnected lead and the battery terminal. If you read negative, swap the meter cables.
Fire up the bike and see what your current does...
