Sorry to be he bearer os bad tidings but the newish,2017, z900 has been subjected to a worldwide recall.
it seems to only affect certain frame/engine numbers and it has to do with the rear suspension.
i have a link, but it is to another forum, hopefully the mods will understand.
this aint a hoax , my bike was checked out by my dealer about two weeks ago.
here is the link. https://www.z900forum.com/index.php/topic,703.0.html