Re: bike cuts off while driving, and wont start till battery is charged
Yep, you're Stator or R/R is bad.
Usually when One dies out, it takes the "other" down with it!
The two components work in tandem. Your Stator has copper coils and generates the charge as your motor spins. That charge immediately goes to the Rectifier/Regulator unit.
It goes to the Rectifier first, which converts the AC to DC...then it moves to the Regulator, which "manages" how much voltage gets to the battery. If that management unit goes bad, it won't regulate jackshit.
(usually the "technical" way they fail...is because of the tiny Diodes. They ONLY allow current to flow One way...but over the years, they can fail, and allow current to flow BOTH ways, and things go haywire.)
I'd steer clear of that "motorcycle shop" too...sounds like they just wanted to make a quick buck and "sell" you a battery and send you out the door!
I guarantee you they didn't test jackshit.
You should have around 13.5v at Idle, and 14-15v as the bike Rev's to around 6k.