Twin Power 90-06 Big Twin and XL with CV Carb CV Carburetor Recalibration KitOur recalibration kit cures throttle flat spots, backfiring and poor throttle response common to the CV carbs. It increases power midrange and top end while maintaining satisfactory fuel economy. This Part Fits: Year Make Model Submodel 1994 2006 Harley Davidson FLHR Road King Base 2004 2006 Harley Davidson FLHRS Road King Custom Base 1990 1993 Harley Davidson FLHS Electra Glide Sport Base 1990 2006 Harley Davidson FLHT Electra Glide Standard Base