The top speed of a Kawasaki Ninja 650 can vary depending on factors such as rider weight, wind resistance, and road conditions. However, the Kawasaki Ninja 650 is capable of reaching speeds of around 120 to 130 miles per hour (193 to 209 kilometers per hour). It's worth noting that riding at high speeds can be dangerous and is typically only legal on designated racetracks or in areas where speed limits permit. It's important to always prioritize safety and abide by the laws and regulations of your specific location when riding a motorcycle.