My 2001 XL1200C was having running problems so I bought this kit. The problems were because the bike has screaming eagle pipes and K & N air filter. When one of previous owners installed it they drilled the pilot out. It was way too big. The stock pilot wouldn't run because it was too lean. Put the stage one tuner kit in my carb (already had the EZ Mixture screw), and the bike runs super now. Very easy to do, hardest part is readjusting the throttle cables.