I used to own a ZZR 400 and I suspect it suffered carb ice.
You would be happily riding and the engine would lose power untill after 30 seconds it would stop. I would pull over to the side of the road and after a couple of minutes it would go again.
Used to get damn frustrating when it would happen 5 or 6 times in a row on the motorway.
Other times it would not happen at all for months, funny thing is was always when I was under power.
Was no longer a problem when it droped a valve at 130 on a back road and ground it's self to bits!
