05-09 KAWASAKI KFX700: Kibblewhite Valve Spring Kit Kibblewhite takes a scientific "system" approach when designing their valve spring kits. Each component is designed to work with the others as part of the complete system. Kibblewhite's engineers use a proprietary design and simulation software, and draw on their 70+ years of design experience to create these systems. Kibblewhite's design, simulation, and manufacturing processes insure compatibility of the valve spring's force and natural frequency with the cam profile, valvetrain mass, system harmonics, and the engine RPM. Kibblewhite spring manufacturing partners are U.S.-based companies that are ISO certified.