Mikuni American's popular HSR42, HSR45 and HSR48mm Smoothbore Carburetor Kits are known world-wide as the best performing carburetors for American V-Twins. The popular Mikuni HSR42 Carb Kit is already an industry performance standard for Sportsers, Buells and stock Big Twins by offering a 25% increase in power and torque when used with an aftermarket exhaust system. More mildly modified Big Twin engines with aftermarket cams and big bore kits can benefit from the extra induction flow provided by the large bore Mikuni HSR45 Carburetor Kit. The all-out racing carburetor for American Big Twin monster motors is Mikuni's HSR48 Easy Carburetor Kit. This huge 48mm smoothbore carburetor offers the highest air flow possible while providing highly accurate fuel metering, more power, and Mikuni's renowned precision throttle response. A new extended main jet and larger fuel valve ssure ample fuel supply for very powerful engines. All Mikuni HSR 42/45/48 smoothbore carburetor offers the highest air flow possible while providing highly accurate fuel metering, more power, and Mikuni's renowned precision throttle response. Carburetors are designed with an 8-roller bearing flat throttle slide assembly that allows an unobstructed venturi at full throttle to flow more air, while it mixes more precisely at all throttle settings. Mikuni's roller bearing throttle slide offers smoother throttle control and allows the use of a lighter throttle return spring for reduced throttle effort. And the Mikuni adjustable accelerator pump provides instant throttle response in any riding or performance application. While a high capacity float bowl prevents fuel starvation even under full throttle applications. Mikuni Replacement and Aftermarket Performance Carburetors, Fuels Pumps, Genuine Rebuild Kits, and all their Parts and Accessories are available from Mikuni American Distributors or through your favorite dealer. You can look up all the available Kits, Carburetors and Parts, along with Mikuni Distributors on the www.MikuniPower.com website.