I have a 2006 zx10 when i reached around 2000 miles i started hearing some top end noise.Everyone i talked to told me it was normal.Bt the noise kept getting louder so icalled a local Kawasaki dealer who told me my warrenty had just ended.I decided to have a look for my self.When i pulled the cams and lifters out there where six intake valve retainers broken.I called Kawasaki to see if anyone else was having this problem this was the first.So now i´m stuck do i go oem parts or go with aftermarket?If anyone has seen this are has any advice i would appreciate it