i just installed a dynojet thunder slide kit in my stock carb.it comes with everything you need new jets and all.part number is DS289307 LOOK ON WEB SITE WWW.dynojet.com this made a huge difference in throttle responce and horse power.you will all so need to get a high flow air filter.i got my kit at the swap meet n charlotte,,paid 50.00 for it and the price at harley was 139.99 so shop around