I'm on my 3rd rec/reg........ Just replace it with the latest model. 13.8 is not enough.
New/good reg. runs 14.4/5 at idle no lights
14.4/5 at rpm lights/no lights
Two invaluable gages are a volt meter and oil temp (correct eng. temp)
A lot of people panic that their bikes are overheating because their cooling system does what it is designed to do. With an oil temp gauge you know what is really happening.
I mounted mine on the glove box