Hi all, aflter cleaning contacts, solving air leaks, etc I measured coils and found this:
coil cyl 1 - 4 no zero, nada, Ohm,
coil cyl 2 - 3  10, 5 kohm. Could it be the cause of erratical idle

Regards

I presume this is measured across the High voltage terminals. They should be around 10000 ohms as one is reading zero it needs to be replaced. There are 2 types for a K100 8v the early ones were a very dark grey and later were black/dark brown with orange towers at the high voltage terminals. The later ones were a much better coil and are interchangeable.
Not sure how you are for import tax etc but I get a lot of gear from EME and find them very good to deal with
http://www.euromotoelectrics.com/category-s/950.htm

Yes, I measured on terminals. Coils are black 1985. Bike was flooded few months ago. Thanks Rick