Larry Cook's specially-designed jet kit for UM V2S-650 and Hyosung GT650 motorcycles. Designed to work with the factory exhaust system in place.

Includes Larry's step-by-step instructions, complete with with pictures. Comes with main jets, pilot jets, carb slide modification for better throttle response, tools for opening carb body, instructions for modifying the air box for improved air flow and instructions for modifying the stock pipes.

Simply the best way to improve performance without changing your entire exhaust system!