Dynojet Jet Kit Yamaha Fz600 Includes Stage1 and Stage 3 jets for stock to modified engines! Features: Increase power and smoothness throughout the entire rev range, while maintaining optimum fuel economy Kit includes comprehensive instructions which show step-by-step installation and testing procedures to ensure a perfect setup every time This stage one kit is fully adjustable to allow the use of well-designed aftermarket pipes and stock replacement air filters In most cases power increases of 5 can be achieved