I got back from my holiday Sunday to find the bike dead as a Dodo, so charged up the battery and tested it. Fully charged it was reading 12.8v.
However, I connected it up and ran my multimeter from the earth strap to the -ve terminal, and without even the key in the ignition found 12v flowing.
Fired the engine up first time and it ran a treat, then tried starting it yesterday, and the starter barely spun. Flat as a pancake again, so the evidence pointing to a short somewhere draining the battery.
I put it back on charge this morning, got 12.8v, reconnected it, fired up the bike fine.
Tested the volts at tickover, got 13, took it up to 5,000rpm, got 14.3, which points to it charging ok.
Switched off, put my helmet and gloves on, tried to start it, nothing again! The starter barely moved, the ignition lights faded out, then the starter solenoid did that clicky thing when you have a flat battery. All the signs pointed towards a flat battery again, turning the ignition on but when I tested it it read 12.8 volts! I stuck it on charge again and the charger switched off after 2 minutes because the battery was full of juice.
So what could be causing this? If it's a seized starter motor (I've had that before on my Virago) then the ignition lights would come on bright until I hit the button, but they don't.
It's all the classic signs of a flat battery, without the flat battery.
Could it be the regulator or rectifier? If it was then the voltage between 1500-5000prm wouldn't be stable at 14.3v would it?
Immobiliser maybe, but when they go a bollock they cut everything off?
Any thoughts?