The parts break-out shows that the F800S and F800ST share the same flywheel and stator design as the F800GS and F650GS twins. The -GS bikes are experiencing an abnormally high rate of stator failures. The apparent cause of the failures is overheating. The stator runs in a very confined space with no provisions for air or oil cooling. Failures seem to start at about 35K miles.
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 to see if F800S & F800ST owners are also experiencing high rates of stator failures as they put more miles on their bikes.
The POLL for the -GS twins is locate here, and you can see that from the voting so far, for bikes in the higher mileage range the failure rate is approaching 50% ....
Please cast your vote!