2019 Kawasaki Ninja H2 SX

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 is anything but gentle and often more than the rider can handle. Dual throttle valve technology was designed to tame engine response while contributing to performance. 

On fuel-injected models, throttle bodies generally have only one throttle valve per cylinder. 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 in improved and power is increased. 

Like other Kawasaki engine management technology, Dual Throttle Valves were designed with the philosophy of “following the rider’s intention, while providing natural-feeling support.” They are featured on many Kawasaki models.

Compared to Kawasaki’s traditional Uni-Trak rear suspension, which mounts the shock unit vertically, with Horizontal Back-link rear suspension, the shock unit is almost horizontal. Kawasaki’s original suspension arrangement locates the shock unit very close to the bike’s centre of gravity, greatly contributing to mass centralisation. 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 centre of the bike, further contributing to mass centralisation. The result is greatly improved handling. 

Another 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 stable. Horizontal Back-link rear suspension offers numerous secondary benefits like this.

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 help prevent the rear tyre from hopping and skidding.

3-mode KTRC combines the traction control technology of both 1-mode KTRC, which provides enhanced stability in slippery situations by preventing wheel slip, and S-KTRC, which helps maintain optimum traction in sport riding situations by predicting the rear wheel slip ratio during acceleration, into a single system.

The convenient handle switch allows the type of traction control to be changed instantly by selecting one of the three modes, even while riding. Modes 1 and 2 maintain optimum traction during cornering, like S-KTRC. Designed with sport riding in mind, they enable sharp acceleration out of corners by maximising forward drive from the rear wheel. Modes 1 and 2 differ in the amount that they intervene. Mode 1, set for dry, good-grip road conditions, maintains the ideal slip ratio to ensure optimum traction. 

Mode 3 operates like 1-mode KTRC, reducing power to allow grip to be regained when rear wheel spin is detected. It is ideal when riding in slippery conditions or in the wet. Enabling riders to easily change traction control character, 3-mode KTRC is Kawasaki’s most advanced engine management system.

Sudden over-application of the brakes, or braking on low-grip surfaces (surfaces with a low coefficient of friction) such as wet asphalt or manhole covers may cause a motorcycle’s wheel(s) to lock up and slip. ABS was developed to prevent such incidents. Kawasaki ABS systems are controlled by high precision and highly reliable programming formulated based on thorough testing of numerous riding situations. By ensuring stable braking performance, they offer rider reassurance that contributes to greater riding enjoyment. 

And to meet the special requirements of certain riders, specialised ABS systems are also available. For example, KIBS (Kawasaki Intelligent anti-lock Brake System) is a high-precision brake system designed specifically for supersport models, enabling sport riding to be enjoyed by a wider range of riders. And by linking the front and rear brakes, K-ACT (Kawasaki Advanced Coactive-braking Technology) ABS provides the confidence to enjoy touring on heavyweight models. Kawasaki is continually working on the development of other advanced ABS systems.

Electronic Cruise Control allows a desired speed (engine rpm) to be maintained with the simple press of a button. Because the rider does not have to constantly control the throttle, this system allows relaxed cruising. This reduces stress on the right hand when travelling long distances, contributing to a high level of riding comfort. 

Electronic Cruise Control is featured on Kawasaki’s Vulcan 1700 / VN1700 Series cruisers and JET SKI ULTRA 300X and 300LX personal watercraft. These models are equipped with an Electronic Throttle Valve system, meaning the throttle valves are not actuated directly by twisting the throttle grip (or pulling the throttle lever); rather, a position sensor on the throttle grip sends a signal to the ECU, which in determines the ideal throttle position. This is how Electronic Cruise Control is able to automatically adjust engine power to maintain vehicle speed when ascending or descending grades are encountered. Without the detailed control offered by Electronic Throttle Valves, functions like Electronic Cruise Control would not be possible.

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 minimise negative impact on the environment.

Kawasaki developed KIBS to take into account the particular handling characteristics of supersport motorcycles, ensuring highly efficient braking with minimal intrusion during hard sport riding. It is the first mass-production brake system to link the ABS ECU (Electronic Control Unit) and engine ECU. 

In addition front and rear wheel speed, KIBS monitors front brake caliper hydraulic pressure, throttle position, engine speed, clutch actuation and gear position. This diverse information is analysed to determine the ideal front brake hydraulic pressure. Through precise control, the large drops in hydraulic pressure seen on standard ABS systems can be avoided. Additionally, the tendency on supersport models for the rear wheel to lift under heavy braking can be suppressed and rear brake controllability can be maintained when downshifting.

Power modes offer riders an easily selectable choice between Full and Low Power. While Full Power is unrestricted, in Low Power mode maximum power is limited to approximately 75-80% of Full. Response is also milder in Low Power mode. Riders may opt to use Low Power mode for rainy conditions or city riding, and Full Power when sport riding. 

Available on the Ninja ZX-14R / ZZR1400, Versys 1000 and other key models, when combined with the 3-mode KTRC (+ OFF) traction control system, Power Mode selection offers a total of eight combinations (KTRC: Mode 1/2/3+OFF x Power Mode: Full/Low) to suit a wide range of riding situations. For example, an experienced rider enjoying sport riding on dry pavement might choose Full Power and Mode 1. On a wet or slippery surface, choosing Low Power and Mode 3 would yield the lowest chance of incurring wheel spin, and with the milder throttle response would offer a high level of riding safety.

Drawing on the know-how and technology possessed by the KHI Group, Kawasaki’s supercharged engine delivers high engine output while maintaining a compact design.  The key to achieving this incredible performance lies in the engine’s supercharger – a motorcycle-specific unit designed completely in-house with technology from Kawasaki’s Gas Turbine & Machinery Company, Aerospace Company and Corporate Technology Division.

One of the greatest benefits of designing the supercharger in-house and tailoring its design to match the engine’s characteristics was that engineers were able to achieve high-efficiency operation over a wide range of conditions – something that would not have been possible by simply dropping in or trying to adapt an aftermarket automotive supercharger.

The importance of high efficiency in a supercharger is that, as the air is compressed, power-robbing heat gain is minimal.  And while many superchargers are able to offer high-efficiency operation in a very limited range of conditions, Kawasaki’s supercharger offers high efficiency over a wide range of pressure ratios and flow rates – meaning over a wide range of engine speeds and vehicle speeds.  This wide range of efficient operation (similar to having a wide power band) easily translates to strong acceleration.  The supercharger’s high efficiency and minimal heat gain also meant that an intercooler was unnecessary, greatly saving weight and space, and enabling the engine’s compact design.

The Kawasaki Engine Brake Control system allows riders to select the amount of engine braking they prefer.  When the system is activated, the engine braking effect is reduced, providing less interference when riding on the circuit.

The strength of Kawasaki’s cutting-edge electronics has always been the highly sophisticated programming that, using minimal hardware, gives the ECU an accurate real-time picture of what the chassis is doing.  Kawasaki’s proprietary dynamic modelling program makes skilful use of the magic formula tyre model as it examines changes in multiple parameters, enabling it to take into account changing road and tyre conditions. 

The addition of an IMU (Inertial Measurement Unit) enables inertia along 6 DOF (degrees of freedom) to be monitored.  Acceleration along longitudinal, transverse and vertical axes, plus roll rate and pitch rate are measured.  The yaw rate is calculated by the ECU.  This additional feedback contributes to an even clearer real-time picture of chassis orientation, enabling even more precise management for control at the limit. 

With the addition of the IMU and the latest evolution of Kawasaki’s advanced modelling software, Kawasaki’s electronic engine and chassis management technology takes the step to the next level – changing from setting-type and reaction-type systems to feedback-type systems – to deliver even greater levels of riding excitement.