I agree. Bike runs off battery and depleats it with not enough juice to restart it.

 

Simple test : Charge the battery overnight, take a multitester and measure the output across the battery -should be +12.5V- if it's not,it's a battery problem.- THEN start the bike, and warm it up,and measure the output across the battery again. At 2500-3000RPM should be 13.5-15V.
If it's not, it's either the stator or the reg/rec.
Measure the output on the three yellow wires from the stator - should read the same for each, around 30V- if one is lower than the others, it's a stator problem.
If first two are OK(battery and stator), all that's left is the reg/rec.
Remember all three components should be working correctly Reg/rec, stator, and battery.- if not, you'll have problems. I ended up replacing all three to resolve my difficulty. I had cooked the windings on my stator, which gave a charge with a new reg/rec, but over time it caused the reg/rec to fail. Hope this helps. If you need more, PM me.
I used the diagnostic chart that Steve_Cardiff mentioned in earlier post above. Helped a lot.