The Yamaha YZF-R6 is a sport motorcycle known for its impressive performance. The top speed of the Yamaha R6 can vary depending on factors such as rider weight, riding conditions, and modifications made to the bike. However, in its stock form, the Yamaha R6 has a top speed of approximately 160 mph (257 km/h). It's worth noting that motorcycle manufacturers often limit the top speed of their bikes to ensure safety and adhere to legal requirements, so the actual top speed may be higher with certain modifications or under specific conditions.