2006 Yamaha YZ450F(W) Owner's Service Manual (P/N 2S2-28199-81)

Yamaha’s YZ450F(W) Owner’s Service Manual, publication 2S2-28199-81, first edition July 2006, covers the 2006 competition model and its U.S., Canadian, European, Australian, New Zealand, and South African market versions. It combines operating guidance, maintenance, internal repair procedures, electrical diagnosis, and race tuning.

• Engine repair: Camshaft and cylinder-head removal, valve and piston inspection, crankcase separation, crankshaft installation, and timing-system assembly.

• Clutch and shifting: Wet-clutch disassembly, friction-plate inspection, transmission gear checks, shift-cam and shift-fork service, and kick-start mechanism repair.

• Fuel and cooling: Keihin FCR MX39 carburetor disassembly, accelerator-pump timing adjustment, radiator-cap testing, cooling-system leak checks, and water-pump service.

• Suspension and brakes: Telescopic-fork overhaul, damper bleeding, Monocross linkage service, brake-caliper and master-cylinder disassembly, and brake-system air bleeding.

• Ignition and TPS: Wiring diagrams, ignition fault-finding charts, coil tests, neutral-switch checks, and throttle position sensor replacement and adjustment.

• Race setup: Carburetor setting examples, suspension troubleshooting charts, spring identification, and optional jet, spring, and sprocket part-number tables.

Owners get operating and routine-maintenance guidance; the internal repair sections suit mechanically experienced users with the specified tools, and Yamaha recommends dealer maintenance for the front fork.

Engine Inspection, Valve Adjustment and Lubrication

The valve-clearance section includes pad selection tables that relate measured clearance and the installed shim to replacement-pad selection. Cylinder-head work extends to valve sealing, stem-to-guide clearance, valve-seat inspection, and guide replacement, with tools such as valve spring compressor YM-4019/90890-04019 identified.

Bottom-end procedures cover crankshaft removal and installation, bearing inspection, and transmission assembly checks. Reference tables provide camshaft runout, piston-ring end-gap, and clutch friction-plate limits, alongside component-specific torque data and torque-check point charts.

Dry-sump lubrication charts and lubrication diagrams trace the oil pump, filter, tank, crankshaft, camshafts, and transmission oil paths. Routine sections also cover break-in checks, air-filter care, oil servicing, cleaning, and storage preparation.

Carburetor Settings and Cooling Tests

The tuning chapter explains how the pilot circuit, main jet, jet needle, and accelerator-pump leak jet affect different throttle conditions. Its symptom-based examples help separate low-speed mixture problems from hesitation during rapid throttle opening.

Carburetor procedures include float-height inspection and accelerator-pump timing adjustment. The TPS handling warning explains why disturbing its mounting screws during routine carburetor work can reduce engine performance.

Cooling coverage includes radiator-cap opening-pressure tests, system leak testing, radiator removal, and water-pump impeller, bearing, and seal inspection.

CDI Ignition and TPS Diagnosis

Ignition inspection charts distinguish wiring faults, ignition-coil problems, magneto pickup and source-coil faults, engine-stop button faults, and neutral-switch faults before CDI-unit replacement is considered.

The specifications distinguish the European 2S2-80 CDI unit from the 2S2-70 unit used in other markets. The wiring diagram includes connector layouts and wire-color codes, while cable-routing diagrams show harness, hose, and control-cable placement.

An illustrative 3-D ignition-timing map explains how engine speed and throttle position influence CDI control. It represents the control principle rather than the actual ignition calibration.

Fork, Linkage and Brake Service

Fork procedures cover seals, sliding components, the base valve, damper assembly, and oil filling. The tool references include cap bolt ring wrench YM-01501/90890-01501. Fork cautions address locknut removal that can trap the damper rod and incorrect damper insertion that can damage the internal valve.

Rear suspension work covers swingarm and linkage bearings, shock removal, springs, and external adjustments. The manual warns against opening the pressurized nitrogen cylinder or reservoir.

Brake sections extend beyond pad replacement to caliper and master-cylinder inspection and reassembly. Use calibrated torque equipment and appropriate protection when handling fluids or pressurized suspension components.

Examples of Valve and Electrical Test Data

These values are a small selection of the manual’s adjustment and diagnostic specifications.

Cold intake-valve clearance is specified at 0.10–0.15 mm in the valve-adjustment material.

The magneto pickup-coil resistance specification is 248–372 ohms at 20°C (68°F). Following TPS replacement, the adjustment section specifies an output of 0.58–0.78 V with the engine idling.

Searchable Text, Bookmarks and Printable Pages

Search and wiring detail: The PDF contains searchable text and bookmarks organized by language and service topic. Some higher-level chapter bookmarks lead to contents pages; individual section bookmarks provide direct topic access. Small connector and wire-color labels in the wiring diagram are best read with zoom.

One printable PDF contains the English, French, and German texts together. The 650-page total already includes the front and back covers, five memo pages, and two blank pages.