2008 Yamaha YZ125X1 Owner's Service Manual OEM (P/N LIT-11626-21-43)

• Official 100-page Yamaha publication (P/N LIT-11626-21-43, first edition June 2007)
• Covers the high-performance 2008 Yamaha YZ125X1 two-stroke motocross models across all regional variants (USA, Canada, Europe, Australia, New Zealand, and South Africa)

Technical Documentation and Workshop Utility

This base technical reference delivers the critical assembly tolerances, fluid capacities, and fastener torque data missing from standard owner handbooks. Mechanics working on the 124 cm3 two-stroke engine will find specific break-in procedures alongside internal inspection criteria for the constant-mesh 6-speed transmission, the YPVS power valve system, and the liquid-cooled cylinder head assembly. Working on high-performance motorcycles involves inherent safety risks, making it critical to verify your approach against these factory specifications before starting any hands-on work. The document outlines the essential inspection parameters required to plan any major overhaul or routine repair efficiently.

Key Specifications and Maintenance Data

Getting the setup right directly impacts track performance. The manual provides comprehensive maintenance tables detailing chassis geometry, suspension settings, and electrical reference values. For example, it documents the 46.0 N/mm rear shock spring rate and a 0.9 liters coolant capacity. You will find precise tightening torque values for critical chassis components, including a 7 Nm steering ring nut final torque, alongside swingarm pivot specifications. Electrical system details cover CDI magneto resistance values and ignition timing. Engine builders can also verify precise factory tolerances using the listed 0.040–0.045 mm piston-to-cylinder clearance standards.