This manual covers the 2003 Softail models, including the FLSTC/FLSTCI Heritage Classic, FLSTF/FLSTFI Fat Boy, FLSTS/FLSTSI Heritage Springer, and FXST/FXSTB/FXSTC Softail Standard/Bad Boy/Custom. These motorcycles are powered by the renowned Twin Cam 88 engine, an air-cooled, 45-degree V-twin displacing 1450cc (88 cubic inches). Known for their iconic styling and robust engineering, Softail models offer a blend of classic aesthetics with a comfortable ride, making them ideal for cruising and long-distance travel. The Twin Cam 88 engine, introduced in 1999, provides substantial power and torque, delivered through a 5-speed transmission and a reliable belt drive final drive. This comprehensive Factory Service Manual is designed to provide detailed instructions for the complete service and repair of your 2003 Softail. It covers all essential systems, including the powertrain, chassis, suspension, brakes, electrical system, and fuel system. Within these pages, you will find procedures for routine maintenance, major repairs, and in-depth troubleshooting, supported by technical specifications, torque values, and diagnostic information. This manual serves as an authoritative resource for owners, independent mechanics, and technicians, enabling them to maintain, diagnose, and repair these motorcycles with confidence and precision, ensuring optimal performance and longevity.