Z650RS

Based on feedback from racing activities, the Assist & Slipper Clutch uses two types of cams (an assist cam and a slipper cam) to either drive the clutch hub and operating plate together or apart.

Under normal operation, the assist cam functions as a self-servo mechanism, pulling the clutch hub and operating plate together to compress the clutch plates. This allows the total clutch spring load to be reduced, resulting in a lighter clutch lever feel when operating the clutch.

When excessive engine braking occurs – as a result of quick downshifts (or an accidental downshift) – the slipper cam comes into play, forcing the clutch hub and operating plate apart. This relieves pressure on the clutch plates to reduce back-torque and helps prevent the rear tire from hopping and skidding. This race-style function is particularly useful when sport or track riding.

Late-model sport bikes often use large-bore throttle bodies to generate high levels of power. However, with large diameter throttles, when a rider suddenly opens the throttle, the unrestricted torque response can be strong. Dual throttle valve technology was designed to tame engine response while contributing to performance.

On models with dual throttle valves, there are two throttle valves per cylinder: in addition to the main valves, which are physically linked to the throttle grip and controlled by the rider, a second set of valves, opened and closed by the ECU, precisely regulates intake airflow to ensure a natural, linear response. With the air passing through the throttle bodies becoming smoother, combustion efficiency is improved and power is increased.

Using high-precision electronic control for engine management, Kawasaki models can achieve a high level of fuel efficiency. However, fuel consumption is greatly affected by throttle use, gear selection, and other elements under the rider's control. The Economical Riding Indicator is a function that indicates when current riding conditions are consuming a low amount of fuel. The system continuously monitors fuel consumption, regardless of vehicle speed, engine speed, throttle position and other riding conditions. When fuel consumption is low for a given speed (i.e. fuel efficiency is high), an "ECO" mark appears on the instrument panel's LCD screen. By riding so that the "ECO" mark remains on, fuel consumption can be reduced.

While effective vehicle speed and engine speed may vary by model, paying attention to conditions that cause the "ECO" mark to appear can help riders improve their fuel efficiency – a handy way to increase cruising range. Further, keeping fuel consumption low also helps minimize negative impact on the environment.

Kawasaki ABS systems use front and rear wheel sensors to constantly monitor wheel speed. Should information from either of the sensors indicate that wheel lock has occurred, the ABS ECU directs the pump in the ABS unit to modulate brake fluid pressure (releasing and reapplying pressure so that traction can be regained) until normal operation resumes. ABS offers rider reassurance that contributes to greater riding enjoyment.

Compared to the Kawasaki traditional Uni-Trak® rear suspension, which mounts the shock unit vertically, with Horizontal Back-link Rear Suspension, the shock unit is almost horizontal. The original Kawasaki suspension arrangement locates the shock unit very close to the bike's center of gravity, greatly contributing to mass centralization. And because there is no linkage or shock unit protruding beneath the swingarm, this frees up space for a larger exhaust pre-chamber (an exhaust expansion chamber situated just upstream of the silencer). With a larger pre-chamber, silencer volume can be reduced, and heavy exhaust components can be concentrated closer to the center of the bike, further contributing to mass centralization. The result is greatly improved handling.

A secondary benefit is that the shock unit is placed far away from exhaust heat. Because it is more difficult for heat from the exhaust system to adversely affect suspension oil and gas pressure, suspension performance is more consistent.