The regulator could be on the engine too. Just above the starter. First thing I would do is check stator voltage. Find the two wires from the stator and disconnect them from the regulator. Hook up your meter leads to the two wires. Set your meter at AC voltage. Start engine. Warm up a little, then turn up to full throttle. Voltage should be around the 28 to 32 AC volts. If not stator is bad. I have never seen a bad one yet.
Noel