Yamaha YFZ450 ATV Service & Owner’s Manual Set, 2004–2009 (P/N LIT-11616-17-11)

The V supplement adds model-specific procedures and specifications to the base service manual. The W/SEW supplement adds further revisions, while the owner’s manual covers riding and routine maintenance.

For complete W/SEW service procedures, Yamaha’s foreword specifies the 5TG2-AE1 base manual and the 5TG-28197-E2 V supplement. This set includes the U.S. editions of those two publications. Match workshop coverage to the model suffixes in the table.

PDF Search, Bookmarks, and File Layout

Search and navigation: The workshop PDF has searchable text and bookmarks. Two supplement contents bookmarks are inactive, and some section bookmarks lead to the contents pages. Small wire and connector labels are clearest when zoomed in. The owner’s PDF has bookmarks and searchable main text, with some image-based pages.

The ZIP contains two printable PDFs, one combining all three service publications and one containing the owner’s manual. The 668-page total includes the original covers, two blank pages in the workshop PDF, and the owner’s two warranty pages, three supplemental pages, and two-page safety card.

Engine Repair, Chassis Service, and Electrical Diagnosis

The selected topics below highlight the main repair and operating material. Other examples include shift-shaft service and front-wheel toe-in adjustment.

• Engine and transmission: Engine removal and installation, camshaft and timing-chain work, cylinder-head and valve service, piston and cylinder inspection, clutch and balancer repair, oil-pump checks, crankcase separation, crankshaft installation, and transmission disassembly and assembly.

• Carburetor: Disassembly and reassembly, accelerator-pump timing, and throttle-position-sensor testing and adjustment.

• Cooling system: Radiator inspection, water-pump repair, and coolant-flow diagrams.

• Chassis and brakes: Wheel, hub, and rear-axle service, brake pad and hydraulic service, steering-stem and tie-rod inspection, front-arm and ball-joint work, shock and relay-arm service, and swingarm and drive-chain inspection.

• Electrical diagnosis: Switch continuity, Throttle Override System (T.O.R.S.), ignition, starting-circuit cut-off, starter motor, charging, lighting, signaling, and coolant-temperature circuit checks.

• Rider operation: Controls, shifting, break-in, pre-ride checks, suspension setup, off-road riding techniques, routine maintenance, troubleshooting, and storage.

Yamaha wrote the service publications for dealers and qualified mechanics familiar with vehicle repair. The owner’s manual gives experienced ATV riders operating guidance and basic inspection and maintenance procedures.

Engine Reassembly and Workshop References

Exploded views and job charts show assembly order, inspection points, replacement criteria, lubrication locations, and tightening specifications. Valve-pad selection charts pair measured clearances with replacement pad sizes for valve adjustment.

Special-tool references include the crankcase separator 90890-01135 / YU-01135-A, crankshaft installer pot and bolt 90890-01274 / 90890-01275, ball-joint tool and attachment 90890-01474 / 90890-01480, valve spring compressor 90890-04019, and rotor puller 90890-04142.

Turning the crankshaft during camshaft installation can upset valve timing, and uneven cam-cap tightening can damage the cylinder head, caps, or camshafts. Solvents or mixed brake fluids can damage hydraulic seals and compromise braking.

Chassis and Supplement Updates

The V supplement updates rear wheel, axle, brake, and suspension procedures, along with cable routing, radiator and water-pump service, and headlight-relay and radiator-fan circuit checks.

The W/SEW supplement covers fast and slow compression-damping adjustments for shocks equipped with both adjusters, inspection and installation of the water-pump oil nozzle, and front brake master cylinder removal. The base manual covers shock removal and inspection and treats the nitrogen-charged units as sealed assemblies.

Wiring and Fault Isolation

Separate wiring diagrams cover the S, V, and W/SEW models. The workshop PDF also includes starting-circuit cut-off and charging schematics, oil-flow diagrams, and cable-routing views.

For a no-charge complaint, the charging checks help separate battery and fuse faults from stator or wiring faults by pairing charging-voltage and coil-resistance tests with the circuit diagram. The troubleshooting chapter also organizes hard-starting faults by fuel, electrical, and compression systems and covers poor running, clutch and shifting faults, overheating, brake and shock problems, unstable handling, and lighting failures.

Riding, Maintenance, and Storage

The owner’s manual illustrates hill climbs and descents, traversing slopes, sliding, crossing water, and riding rough terrain. It also explains cold starting, parking, and loading.

Routine service includes oil and coolant changes, air-filter and spark-arrester care, brake and clutch adjustments, chain and chassis lubrication, battery and fuse service, wheel removal, and headlight bulb replacement. Rider troubleshooting charts cover starting, poor performance, and overheating.

Valve Clearance and Rear Brake Pad Spec Preview

For the YFZ450S, cold valve clearance is 0.10–0.15 mm at the intake and 0.20–0.25 mm at the exhaust.

The W/SEW supplement lists a standard rear brake pad thickness of 5.4 mm and a wear limit of 1.0 mm for both the inner and outer pads.