I'm not very good at explaining stuff, sorry.
If you are testing the system as i said with the battery
in circuit, you should get around 14.5 volts at 2000 rpm with no lights on.
This voltage may take a while to get up to that if the battery
is not very good.
When you let the bike idle, the voltage will drop as the alternator is probably not able to run the ignition and keep the battery
on charge at around 800-1000 rpm.
If you have measured the stator leads as mentioned before, the stator is ok. All 3 phases should be working if you measure across any two leads and read less than 2 ohms.
You need to do this for all the combinations of the 3 wires. Example: A-B A-C B- C And any phase to Frame, if there is a circuit to frame the stator is faulty or one of it's
wires has lost it's insulation.
With the stator being ok, the rotor needs to be well magnetized for a good output and the air gap needs to be around 8 thou all around the fitted rotor.