How to Remove the Speed Limiter on Kawasaki 400?
3 Answers
Methods to remove the speed limiter on Kawasaki 400: Replace the original ECU or reprogram the vehicle's computer to remove the speed limiter, allowing the bike to reach a top speed of 195 km/h. The Kawasaki 400 is speed-limited to 135 km/h in China. While removing the limiter enhances the riding experience, it's crucial to prioritize safety. Extreme speeds should only be attempted on tracks, and traffic rules must be strictly followed on public roads to ensure the safety of both the rider and others. The Kawasaki 400 measures 1990mm in length, 710mm in width, and 1120mm in height, with a wheelbase of 1370mm, a minimum ground clearance of 140mm, and a total weight of 168kg.
Speaking of removing the speed limiter on the Kawasaki 400, I've tried several methods. The most common approach is flashing the ECU, using specialized equipment to rewrite the program parameters and remove the factory-set RPM limit. Another option is installing an aftermarket ECU to directly take over control signals. Modifying the transmission system is also effective—replacing the front sprocket with a smaller one or the rear sprocket with a larger one essentially achieves speed derestriction. However, it's important to note that removing the limiter increases engine load, so it's necessary to check the cooling system and potentially upgrade the oil and cooling. Additionally, the braking system may not keep up with the improved acceleration, so upgrading to high-performance brake pads is recommended. I personally tried flashing the ECU, but it requires an experienced technician to avoid triggering fault codes. After derestriction, the top speed can reach around 180 km/h, but speeding on public roads is extremely dangerous.
Having modified motorcycles for over a decade, removing the speed limiter on a Kawasaki 400 requires starting with the electronic control system. ECU tuning is crucial—either modify the speed limit threshold using diagnostic equipment or install a piggyback computer to bypass the restriction. Fine-tuning the drivetrain is another option, such as changing the sprocket combination with different gear ratios. However, post-modification risks are significant: prolonged high RPMs can cause engine overheating and shorten component lifespan. Emissions may also exceed standards, affecting annual inspections. Last week, a customer fried their ECU module due to improper wiring, costing over 3,000 in repairs. I recommend upgrading the cooling and lubrication systems first. After modifications, always test braking performance. Speeding on public roads leads to tickets—if you really want to race, do it safely on a track.
