Lléo - thanks for your post!
Your English is much better than my Polish would be I can assure you of that!
I guess the F800S & F800ST do have the same issue this is a shame!
To summarize the possible
fixes ... I think we have:
- The oil cooling modification to the flywheel (Buell is doing this in their "works" )
It has the possibility of compromising engine lubrication (will it ... I have no idea... but there's a chance).
I think this will fix the stator issue ... even a modest amount of oil for cooling should drop the temp. of the stator enough to keep the insulation from failing.. someone would need to measure temperatures of the stator in use before and after the modification to confirm...
- I'll have to find the link, but someone from Buell was drilling small holes around the perimeter of their flywheel to promote air circulation thus cooling the stator ... this should help, but I have no idea if it will totally fix the problem ... again ... someone would need to measure temperatures of the stator in use before and after the modification to confirm...
- The series style R/R.
We have several riders using this successfully.
IMHO, it has the possibility of causing issues with the CANBus (will it ... I have no idea... but there's a chance).
- BMW's new open flywheel design, which may also include changes to the stator
I'm pretty confident that this will work, and is a fully supported fix, but alas a very expensive if out of warranty.
- "Detuning" the stator - Joel and I kicked this around - if small resistors were added in series with each of the three stator leads (say 0.1 or 0.2 ohms) this would reduce the output of the stator and thus reduce the I^2*R heating of the stator coils potentially fixing the problem ... Albeit at the expense of reduced output by the alternator. Perhaps reducing the out put from 400W to something like 350W. This modification could be done so as to make it easily reversible for winter riding or heavy electrical loads... again testing required to confirm...
- As I've mentioned somewhere, I have reported the details of our stator issues to ElectroSport a company that mfg. stators, and they have a design in test that they believe will fix the problem. If their testing works out, this is probably the cheapest and most reliable fix - at less than $150 USD.
I'll send my contact an e-mail today asking for an update on this............
Ok ... did I miss anything?