[MadisonMotorsportUK]

I would say the chances are a failing stator. If it were the reg/rec I'd expect it more likely to go over-voltage.

Check the stator output voltages as I suggested earlier.

 

[Tinsnips]

You should be seeing close to 14V at 5000 rpm. I would double check all connections and grounds & repeat the test. If it fails again you have a charging issue.