Motorcycle Repair: 1986 Virago 750 - Dead Battery/Loss of Power, buckets of money, virago 750

Question
Hi Wayne, I just bought this bike and it seems as if the battery power is drained/depleted in some way.  I charged the battery (still relatively new battery), put it back in the bike and did about 50km's with it parked it, then tried to start it later the afternoon - it was dead like road kill!  Took the battery out, charged it again -  put it back in the bike - and the bike started without a problem. Same thing then happened again - dead battery - took the battery out, and the cable was loose - so fixed that problem, but it still only shows 11.8VDC when the motor is running.  I am now very reluctant to use the bike for I am not sure where this bike will leave me stranded again.  Someone tested the voltage for me at the cables to the battery, with a running motor at 2000rpm's and it gave 11.8volts - what could be the problem?  The battery, disconnected and fully charged also showed ~12VDC - so not exactly sure what was measured when the bike was running - the battery power - or the stator efficiency. I am really reluctant to start putting buckets of money into it before I can get someone who know bikes, advice.

Any suggestions - what else can we check?  Or how else can I check to see where the problem is without spending these mega bucks at a repair shop?

Can anyone out there please help - any suggestions??  thanks a million .. I'll really appreciate it.

Happy biking!  

Answer
Jen,
have you checked all the fuses?
The battery voltage should read 13.2 to 13.8 volts
when the bike is running, so the bike is not charging.
Make sure you check any connectors around the battery
and clean them if need be.
The stator is sometimes the culprit,
it has three wires, usually yellow or white, coming
up from the engine. These wires should have
continuity with each other but not to ground.
When running they send out about 40-60 volts with
the meter set on AC and the wires disconnected
from the bike.
If the stator is okay and the battery as well,
it is time to replace the regulator/rectifier.

You can test the stator from outside if you can
find the 3 white wires and unplug it's connector
while testing it.