This workshop service and repair manual provides comprehensive coverage for the 2003 Aprilia MY660 Motorcycle, specifically focusing on the MY660 Engine. Aprilia, an Italian manufacturer renowned for its sporty and performance-oriented designs, has engineered the MY660 to deliver an exceptional riding experience. This manual is designed to empower owners and technicians with the detailed knowledge required for expert maintenance and repair, ensuring the longevity and optimal performance of this finely tuned machine. The scope of this 175-page English-language manual is extensive, covering critical areas such as engine assembly, disassembly, lubrication, cooling, fuel delivery, ignition, exhaust, emissions control, and diagnostics. It details gearbox internal components, clutch operation, shifting mechanisms, and troubleshooting gearbox issues. Maintenance procedures, including fluid checks, filter replacements, and valve adjustments, are thoroughly explained. Furthermore, the manual offers in-depth repair procedures for engine and gearbox components, common fault diagnosis, and critical technical specifications, all presented with detailed photographs and diagrams to facilitate understanding and execution.