What is the fastest production motorcycle?

The current fastest production motorcycle is the ZX-14. The Kawasaki motorcycle, has been documented officially (with standardized pro-grade speed measuring equipment) to have broken 200 mph and beyond in multiple instances, both by professional riders and amateurs running a speed course.

The previous record holder was the Hayabusa at around ~195 mph maximum, with most record attempts achieving 185-190 mph.

The closest contender to the previous Hayabusa was also a Kawasaki. The ZX-12r. While the 12r did have 5 more hp more than the Hayabusa, its aerodynamics were not as efficient as the Hayabusa's, which translated to slightly slower top speeds.