The 640 LC4, produced in 2003, is a robust dual-sport adventure motorcycle renowned for its powerful LC4 engine. This single-cylinder, liquid-cooled engine, approximately 625cc, delivers a strong balance of torque and performance suitable for both on-road commuting and off-road exploration. The heritage in off-road racing is evident in the 640 LC4's durable construction and capable design, featuring a steel trellis frame, substantial ground clearance, and hydraulic disc brakes. This model represents a segment of the market that prioritizes capability and reliability for adventurous riding.

This manual serves as a comprehensive guide for owners and technicians, covering essential operations, routine maintenance, and basic troubleshooting for the 640 LC4. It details procedures for the engine, fuel, cooling, lubrication, electrical, braking, suspension, and wheel systems, along with controls and instruments. Key maintenance tasks such as oil changes, filter replacements, and pre-ride inspections are explained. While it focuses on owner-level care and basic problem-solving, it does not delve into in-depth repair procedures, providing a clear scope for maintaining the vehicle's performance and longevity.