So..the battery was reading 12.7V after a charge up. I put it back in, and at the same time took off the starter relay and applied some WD40. As I fired her up, the voltage dropped to about 11.6V. Everything worked normally, and at idle, the reading was 11.7V, rising to 12.8V at about 3000rpm. Not sure about what happened there, but all seems fine at mo. Could have been the relay I guess.
Hey, Booger... Reread the posts but didn't see what year and model you're working with. But a couple points about the bike may be of assistance, reminder or interest to you.
The battery is responsible for powering the lights, ignition and any other loads you have powered up. The voltage drop is not unusual, per say, but could indicate an aging/failing battery.
The generator/alternator does not power the ignition, lights, etc. It's job is to detect battery voltage drop and send a charge to "top 'er up".
Also, you need to have about 2000 revs on the clock for the alternator to be able to do its thing. You may occasionally read about riders having voltage problems if they are stuck in slow moving traffic for extended periods. The GEN light may come on and/or flicker.
After cleaning relay plug-in connections, wire junctions, etc consider applying a bit of dilectric grease as a corrosion protection. WD40 will evaporate and you're right back to no protection. Also, check any and all grounds (earth) you can find including the battery's grounding cable.