2008 Yamaha YZ450F / YZ450FX Owner's Service Manual (P/N 2S2-28199-82)

• Covers the 2008 Yamaha YZ450F and YZ450FX competition motocross models across USA, CDN, AUS, NZ, and European regional variants
• Original OEM publication, first edition (May 2007), bearing part number 2S2-28199-82
• Features 574 pages of technical diagrams, exploded views, torque specification tables, and routing schematics
• Serves as the foundational reference used for the 2008 YZ450 series factory service build

Technical Overview and Data

When tearing down a high-performance motocross engine, having exact factory tolerances is critical. This manual provides the exhaustive technical documentation needed for the 2008 Yamaha YZ450F and YZ450FX. You will find dedicated chapters breaking down general specifications, regular inspection intervals, and complete engine service. It also details chassis maintenance, electrical system diagnostics, and professional tuning parameters for the workshop.

Specification Highlights

Digging into the engine parameters, the documentation outlines the 12.3:1 compression ratio and 449 cm³ displacement specs. Assembly data is highly precise. For instance, cylinder head bolt torque values are mapped out in a multi-stage sequence that includes final-stage angles of 180°. You will find the spark plug gap listed at 0.7–0.8 mm in the maintenance tables, alongside a complete cooling system capacity of 0.99 liters. The internal tolerance charts specify a strict piston-to-cylinder clearance of 0.020–0.045 mm. Because working on high-compression race engines carries inherent physical risks and a high potential for mechanical failure, always cross-reference these specification values with your current workshop conditions and verify all safety protocols before applying torque.