Dynojet Stage 1 / 2 Jet Kit Yamaha Xv1600 Kit includes stage 1 and 2 jets for stock and 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