My Kit was designed with the consideration that a "Dyno-Jet" kit would be installed.Although not absolutely necessary, this jet kit is a vast improvement over the factory H-D setup.The particular jet kit I selected is Dyno-Jet's (Part No. 8105), which is for all 883, 1200, and 1340 Twins from 1996 through 1999! Any H-D dealer can provide this kit, and sometimes they carry it in their "Screaming Eagle" line with a different part number. Just ask for the kit for bikes and years just mentioned. The details of this kit are as follows: It comes with a lighter diaphram spring that lets the slide raise quicker for better throttle response. (2) drill bits are included to drill out the mixture screw plug, and the other is for opening up the vacuum signal hole for better throttle response. It comes with a new needle jet, and a needle with (6) adjusting clip positions for better tunability. Use the 3rd clip from the top in all cases. There is an array of jets including the sizes you will need. For high altitude, use the 160 Main jet, and for sea level, use the 170 Main jet. The 175 Main jet might be needed for HOT sea level use. It comes with a richer accellerator pump nozzle that you should not use, and the #45 pilot jet is not included, and should be bought at your local H-D dealer. These kits usually retail for under $100.00, and are easy to install. When shopping for a used carb, you might get lucky and find one with this kit already installed. Lift up the slide against it's spring tension, and you will find that the one with the kit is much easier to lift. If you are allowed to open up the top of the diaphram to expose the needle, look for (6) notches for the clip. The stock carbs have no adjusting clips!