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

This Yamaha-issued Owner's Service Manual is the May 2007 first edition for the 2008 YZ450F(X), document no. 2S2-28199-82. Yamaha specifies the motorcycle for closed-course competition use only. The routine-service chapters are usable by an experienced owner, while internal engine, brake, and fork repair is suited to mechanics comfortable with precision measurement, specialty tools, and race-bike setup.

• Exact regional coverage: YZ450FX for USA, Canada, Australia, and New Zealand; YZ450F for Europe and South Africa. Model codes are 2S2B (USA/Canada), 2S2C (Europe), and 2S2E (Australia/New Zealand/South Africa).
• Top-end engine repair: Covers camshaft and timing-chain service, cylinder-head removal and inspection, rotation-angle head-bolt tightening, valve and spring work, valve-clearance pad selection, and cylinder/piston inspection and assembly.
• Engine teardown and bottom end: Takes the job through engine removal, crankcase separation, crankshaft installation, balancer and oil-pump service, clutch inspection, kick/shift shaft work, and the five-speed transmission, shift cam, and shift forks.
• Fuel, cooling, and electrical systems: Details FCR-MX39 carburetor disassembly, float and accelerator-pump checks, radiator pressure testing, water-pump service, CDI ignition fault isolation, spark tests, and throttle-position-sensor testing and adjustment.
• Chassis repair: Handles wheels and bearings; front and rear calipers, master cylinders, and hydraulic brake bleeding; steering and swingarm bearings; internal front-fork damper and seal work; and rear-shock spring and bearing service.
• Race maintenance and tuning: Brings together pre-operation checks, race-based service intervals, torque tables, capacities, wear and clearance limits, electrical test data, carburetor jetting by symptom and conditions, final-drive options, and fork/rear-shock setup charts.
• Workshop visuals: Provides the Lubrication Diagrams, Cable Routing Diagram, Electrical Components and Wiring Diagram, Ignition System inspection chart, Throttle Position Sensor System test diagrams, and carburetor/suspension setting charts, plus exploded job views for major assemblies.

Regional Details and Factory Tools

Regional content goes beyond the model name. The specifications distinguish the European CDI unit, chassis geometry and rear-tire fitment, rear-shock dimensions and settings, and muffler packing from other markets. Engine-oil guidance and special-tool numbering also change by region.

The tool list pairs U.S./Canada YM/YU numbers with 90890-series numbers used elsewhere. Examples include the YU-A9642/90890-04152 crankcase separator, YM-4019/90890-04019 valve-spring compressor, YM-A0948/90890-01502 fork-seal driver, and YM-34487/90890-06754 dynamic spark tester/ignition checker.

Repair Depth, Limits, and Cautions

Removal and disassembly chapters begin with an exploded view and job chart, followed by inspection criteria, service limits, fastener sequences, lubrication or sealant locations, and installation checks. The electrical chapter is race-bike specific: engine-stop and neutral switches, CDI magneto and ignition-coil tests, spark fault tracing, and TPS diagnosis are covered rather than street-lighting equipment.

The rear-shock chapter covers removal, inspection, spring and bearing work, installation, and external adjustment, but not internal rebuilding of the nitrogen-filled cylinder or reservoir. Nitrogen extraction for disposal is specifically marked for Yamaha dealers.

During engine repair, forcing reluctant crankcase halves can damage the gasket mating surfaces, while careless impeller-shaft installation can cut the water-pump oil-seal lip or dislodge its spring. The TPS section warns that over-probing the connector can compromise its waterproofing or create a short that damages electrical components. Fuel, brake-fluid, hot-surface, and pressurized-suspension warnings are tied to the relevant procedures.

PDF Page Breakdown

The 574-page PDF contains a 183-page English section, a 194-page French section, and a 192-page German section, plus the front and back covers and three blank separator pages.