The 501, produced in 1999, is a high-performance, liquid-cooled, single-cylinder, 2-stroke off-road motorcycle renowned for its distinctive design, including potential under-seat exhaust routing, and a strong emphasis on light weight and pure performance. As a competitor in the demanding enduro and motocross segments, it was known for its raw power, typically estimated between 50-60 HP, and robust construction, often featuring advanced suspension components from manufacturers like WP or Öhlins depending on the specific variant. This model represents a mature iteration of the 500cc platform, benefiting from continuous development and the brand's Swedish heritage, later integrated with KTM manufacturing.

This comprehensive service and repair manual provides essential information for maintaining and troubleshooting the 501. It covers a wide array of systems, including detailed engine overhaul procedures, gearbox maintenance, chassis and suspension adjustments, brake system servicing, and electrical system diagnostics with wiring diagrams. Additionally, the manual details routine maintenance schedules, common wear items, and troubleshooting guides for potential issues. Its depth of coverage is suitable for professional technicians and advanced enthusiasts alike, ensuring the optimal performance and longevity of this specialized off-road machine.