Originally Posted by Ride-a-lot
I believe my bike is in the early stages of the stator crapping out. I have an '09 F650GS with 41K miles. I have always had a volt meter on the bike. Since day one it has consistantly run from 14.1-14.3 volts. I just returned last weekend from a 2000k mile trip, the volts had stayed in the normal range the entire trip.
This week riding to work the volts have been running in the 13.4-13.9 range. I have never seen this low of volts before. This is in warm weather with no extra electrical loads. At times at speed the volts will go up to 14.1 but as soon as I stop the volts drop down to 13.4 The normal volts at idle has always been 14.1-14.2
I will keep riding it and watching for any more signs of charging failure. I will also be watching Electrosport for the release of their stator. I don't want to pay BMW's bloated price. Oh bother!
The check is not hard ... you have have lost one-phase....
Resistance of windings from the stator - a 3-pin connector (1-2, 2-3, 1-3) should all be ~3.5ohms.
At 4K rpm AC output should be ~75V across any pair
The windings should NOT conduct to ground (should be insulated from ground connection)
For details see: http://www.advrider.com/forums/showthread.php?t=685465