First you start the bike, (having removed the seat to access the battery). Then get your trusty VOLT/OHM meter, turn it on, set it to DC VOLTS and put the RED lead on the POSITIVE side of the battery, then put the BLACK lead on the NEGATIVE side of the battery. Twist the THROTTLE untill you are at around 2000 RPM, the meter should read anywhere from 13.5 to 14.5 VOLTS/DC. If it does not, you are not charging. Shut the engine OFF. Next, at the front right of the bike, (right behind the front header) there is a plug connection made of RUBBER. It has 2, TWO prongs, pull the plugs apart. Next, start the engine, using your meter again, set it to AC VOLTS, stick the leads into the FEMALE side of the plug, (it doesn't matter which lead goes into which socket, since we are dealing with AC VOLTAGE) Again, twist the THROTTLE to around 2000 RPM, you should have around 40-45 VOLTS AC, if not, your STATOR is bad. Replace it. If you have good output at the STATOR, your REGULATOR is bad, or has a poor GROUND. To check for a poor GROUND, set your meter to OHMS, put one lead on the REGULATOR, (where there is NO paint) and the other lead to a known good GROUND. (like the engine block) The meter should read INFINITY, i.e. ZERO OHMS, any resistance here is not good. Hope this helps you. Good luck.
AB