As However, it's possible that there may have been developments or new accessories introduced after that time. To the best of my knowledge, Harley-Davidson motorcycles typically use a fuel injection system to deliver fuel to the engine.
If you are referring to an aftermarket product or a specific accessory known as a "fuel pack," it might be related to a fuel management system. Fuel management systems are often used to optimize the fuel-air mixture ratio and improve engine performance. They can adjust parameters such as fuel delivery, timing, and air-to-fuel ratios. These systems allow riders to fine-tune their motorcycle's performance to match their preferences or modifications made to the bike.
Please note that my information may not be up to date, so it's recommended to consult the latest Harley-Davidson documentation or contact an authorized Harley-Davidson dealer for the most accurate and current information regarding any specific accessories or components.