YZF-R6

In 2006, Yamaha advertised that the R6 had a redline of 17,500+ rpm. This is 2000 rpm higher than the previous R6 model and it was the highest tachometer redline of any 2006 production four-stroke motorcycle engine. YZF-R6 Fairings
If it was actual Yamaha engine rpm, it would be near rpm levels known only in Formula One engines, where valve spring stress problems lead to the adoption of pneumatic valve actuation to handle more than 19,000 rpm.motorcycle fairings