It seems there have been many stator failures in the F800GS & F650GS twins due to overheating.
The stator runs in a very confined space with no provisions for air or oil cooling.
BMW has recently released a redesigned flywheel which will likely remedy the problem.
You can read all about it here:
www.advrider.com/forums/showthread.php?t=706033
Post
#399 has pictures of the new and old parts ...
Unfortunately, for those of us that are out of warranty, the new "generator set" is ~$900 USD.
The purpose of this POLL thread is two-fold:
1) Capture failure data vs. mileage (please vote even if you have NOT had a failure)
So as to determine the extent of this problem, and at what mileage failure is likely...
2) To PLEAD WITH ALL USA OWNERS that have experienced a failure to file a complaint with the US Government, regarding the issue esp. if you experiences surging or stalling (I would expect stalling) during the failure incident. (See post
#420 of the above thread for details). This may help get resolution for the issue.
File a complaint(s) here:
https://www-odi.nhtsa.dot.gov/ivoq/