2012 Yamaha YZ450F(B) / YZ450F Owner's Service Manual (P/N 33D-28199-82-E0)

The 2012 Yamaha YZ450F(B) Owner's Service Manual, document code 33D-28199-82-E0, covers the YZ450FB and YZ450F competition models for the US, Canada, Europe, Australia, New Zealand, and South Africa.

Text search and diagram detail: Most text is searchable, with bookmarks for the eight chapters and their main sections. The opening safety note and the contents of the valve pad selection tables are not searchable. Small labels in the main wiring diagram require zooming.

• Engine repair: Engine removal, crankcase separation, crankshaft installation, cylinder-head and valve service, camshaft timing, and piston inspection.

• Clutch and transmission: Wet-clutch disassembly, friction-plate and spring checks, shift cam and shift fork inspection, and geartrain reassembly.

• Fuel injection and ignition: Keihin throttle-body service, fuel-pressure testing, throttle position sensor adjustment, FI fault-code diagnosis, and ignition troubleshooting.

• Cooling and lubrication: Radiator and cap pressure tests, water-pump seal and bearing service, oil-pump inspection, and engine lubrication diagrams.

• Chassis repair: Telescopic front-fork disassembly, steering-stem and swingarm bearing service, brake caliper and master-cylinder repair, and hydraulic brake bleeding.

• Suspension tuning: Rear shock absorber removal, spring and bearing replacement, preload and damping adjustments, and suspension setting charts.

The repair chapters are intended for readers with Yamaha motorcycle servicing knowledge and practical skills; valve-clearance work carries the same requirement.

Regional Builds and Service Specifications

The electrical specifications identify ECU codes 33D7 for the US/Canada, 33D4 for Europe, and 33D6 for Australia/New Zealand/South Africa. Regional tables also distinguish rear gearing, tire sizes, suspension springs, and baseline damping settings.

Maintenance intervals and pre-operation inspection checklists accompany component-specific torque tables, chassis geometry, fluid capacities, wear limits, and electrical test specifications.

Engine, Clutch, and Transmission Repair

Top-end coverage includes cylinder-head warpage checks, titanium valve and guide inspection, decompression-system checks, and intake/exhaust valve pad selection tables. Exploded assemblies show component order and job notes.

Internal repair sections address balancer-shaft alignment and transmission dog, gear, and shift-fork wear. Crankshaft work specifies the separating and installing tools required.

The camshaft section warns that uneven cap-bolt tightening can damage the cylinder head, caps, or camshafts.

FI Diagnosis and Electrical Testing

The Sensor Operation Table and diagnostic-code tables cover sensor readings, injector and ignition-coil actuation, fault-history display, and code erasure. Fault-specific troubleshooting charts distinguish wiring and connector faults from sensor or ECU failures, helping narrow starting and running problems before component replacement.

These tests use the FI diagnostic tool YU-03182/90890-03182, sub-wire harness YU-03212/90890-03212, and an external battery because the machine has no onboard battery. Power Tuner setting-history checks and setting-map erasure are also documented.

Electrical references include the wiring diagram, wire-color and connector views, cable routing diagrams, and sensor voltage/resistance specifications.

Fork Service and Rear Shock Coverage

Front-fork procedures cover damper and base-valve inspection, seal replacement, oil filling, and air bleeding. An assembly warning explains how dropping the damper into the inner tube can damage its internal valve.

Rear shock coverage includes removal, spring and bearing replacement, and external adjustments. It does not include an internal overhaul of the nitrogen-filled cylinder or reservoir.

Suspension setting charts relate handling symptoms to spring, oil-volume, and damping checks. Optional spring and sprocket part numbers support race setup.

Always verify your specific model requirements and consider consulting a certified professional before handling complex engine or chassis work.

English PDF and Included Pages

Supplied as one printable English PDF. The 223-page file includes 216 numbered chapter pages plus seven opening pages containing the cover, safety note, foreword, manual-use instructions, and tables of contents.