Did you test the stator under load, or just measuring the Vac output at the plug as the rpm changed? That can sometimes show an OK stator even when there are burnt coils.
I suggest opening the derby cover or the chain tensioner inspection place (if equiped) and taking a sniff. If the fluid smells burnt, then it is very likely that you have some burnt coils. A better check is to open up the primary, pull the compensator, clutch basket and chain, and then pull the rotor to visually inspect the stator for burnt coils.
If the stator checks out from a visual inspection, then I would replace the VR.
TQ