Not gonna believe this one, but I just found my bike on google image search. I typed in XS400 DOHC ratbike and came across a bike which looked very similar to mine. When I found a few more pics, it turned out to have the exact matching license plate 
Not the previous owner, but the one before that, was active on a Dutch motorbike forum website. So I found back all his old posts, about him telling people who he got the bike from, all the way to his ad selling it on again. Now I know:
- my XS has a steel brake line up front
- the flasher relay which I had trouble with before, is not the original (that's probably why)
- the flashers were traded with another active member of that forum
- the bike was originally blue
- this owner replaced the tail light, the dials on the dash and stuffed the cork (yes, the part from a wine bottle) in the tachometer hole in the engine
- he took very good care of the bearings, carbs, engine, brakes and all other maintenance. As I can read back his posts with dates, I can see he changed the oil at least once a year for 3 years, and he loved the XS dearly.
- the stuff that looks like heatwrap on my exhausts, is actually a 5-euro-per-25-meters glass fiber tape
awesome
Not the previous owner, but the one before that, was active on a Dutch motorbike forum website. So I found back all his old posts, about him telling people who he got the bike from, all the way to his ad selling it on again. Now I know:
- my XS has a steel brake line up front
- the flasher relay which I had trouble with before, is not the original (that's probably why)
- the flashers were traded with another active member of that forum
- the bike was originally blue
- this owner replaced the tail light, the dials on the dash and stuffed the cork (yes, the part from a wine bottle) in the tachometer hole in the engine
- he took very good care of the bearings, carbs, engine, brakes and all other maintenance. As I can read back his posts with dates, I can see he changed the oil at least once a year for 3 years, and he loved the XS dearly.
- the stuff that looks like heatwrap on my exhausts, is actually a 5-euro-per-25-meters glass fiber tape
awesome
