2002 Yamaha YZ250(R)/LC Service Manual (P/N 5UP-28199-30)

This 583-page official Yamaha publication (P/N 5UP-28199-30) serves as the primary technical resource for the 5UP-series build. It comprehensively documents all internal components and chassis assemblies for the 2002 YZ250(R) and YZ250LC motocross motorcycles.

Delivered as an instant download the moment your payment clears, the file features complete full-text search capability. This allows mechanics to locate any part number or specific torque value in seconds, streamlining bench work and reducing downtime in the shop.

Component and Systems Documentation Designed for deep-dive diagnostics and routine maintenance, the manual includes a dedicated 105 pages strictly focusing on detailed torque-check points, electrical wiring diagrams, and component-specific maintenance procedures. It outlines exact maintenance intervals, carburetor jetting setups, and suspension tuning parameters. You will find complete coverage of engine assembly, transmission procedures, and exact torque sequences for the frame, engine mounts, and control assemblies.

Specification Highlights and Reference Data The documentation provides significant technical depth through extensive reference tables, eliminating guesswork during engine assembly. Critical measurements include:

• Piston-to-cylinder clearance: 0.045–0.050 mm
• Clutch housing radial clearance: 0.030–0.055 mm
• Cylinder head nut torque: 25 Nm (18 ft-lb)

Electrical troubleshooting is equally precise. The ignition timing is strictly set at 0.18 mm B.T.D.C., and the CDI source coil 1 resistance is documented to measure between 720–1,080 ohms at 20°C. Note that intake valve clearance is not applicable for this 2-stroke power unit.

Note: Working on high-performance competition motorcycles involves handling pressurized systems and highly flammable fluids. Always review the pre-operation checks and general safety sections provided in the introductory chapters before beginning any teardown or chassis adjustment.