Under the notice, all bikes already delivered to customers and those at dealers had to be returned to Kawasaki. The cause was said to be unexpected engine behaviour, but an official reason wasn’t disclosed at the time.
Now, though, it seems that Kawasaki engineers have got to the bottom of the problem. A statement from the company reads:
"It had been discovered that when some examples of the new 2011 Ninja ZX-10R were operated at high rpm under unique riding conditions - such as operating on a racetrack - the intake valve springs could surge. Should this rare incidence occur it could cause one or more intake valves to seat improperly, resulting in poor engine performance.
"Having examined the very small number of machines which exhibited this surge phenomenon, the Kawasaki factory engineers have designed and fully tested a countermeasure which solves the problem without affecting any facet of the new engine’s outstanding performance.
"On the limited number of machines produced so far, the camshaft, valve springs and spring retainers for intake valves are being replaced to prevent the valve spring from surging. The same design update is automatically being incorporated into the ongoing production run of the newest and most powerful Ninja yet produced."
The European launch of the bike, which was delayed because of the technical issues, is now expected to be at the end of January 2011. In the UK, the Kawasaki Ninja ZX-10R will be priced at £11,699, with ABS costing an additional £1,000.
