The Mikuni HSR42 Easy Carburetor Kit replaces stock CV carb for better performance, more power and dependability. It features a two-piece throttle slide that rolls on stainless bearings for smoother operation, excellent throttle response, and easier starting. The 42mm carburetor smoothbore Venturi creates great airflow, while the enlarged needle and seat provide extended full-throttle operation. The adjustable accelerator pump gives you the best motorcycle performance with instant throttle response at any RPM, and the light throttle return spring makes for easy pull operation. The Easy Carbutaotr Kit works with stock manifold and throttle cables, choke cable, and air cleaner. This kit includes the carb adaptor. High-flow air filter such as 400-639 recommended for maximum performance.; Replaces stock CV carb Stainless bearings Pre-jetted 42mm carburetor smoothbore Enlarged needle and seat Instant throttle response at any RPM Easy pull operation Works with stock manifold and throttle cases Includes carb adaptor Use with high-flow air filter