🏷️ Basic Information

Make:

Yamaha

Model:

YFZ450 / YFZ450S

Model Years Covered:

2003, 2004, 2005, 2006, 2007

Chassis Codes:

Refer to specific model year designation within manual

Generation Designation:

First Generation

👋 Introduction

Segment:

High-Performance Sport ATV

Key Competitors:

Honda TRX450R, Suzuki LT-R450, Kawasaki KFX450R

Vehicle Focus:

Aggressive styling, powerful engine, agile handling, off-road performance.

Benefit To Owner:

Empowers owners to perform comprehensive maintenance and repairs, saving time and money, and ensuring optimal performance and longevity of their YFZ450.

📋 Manual Details

Primary Coverage:

Complete Factory Service / Repair / Workshop / DIY

Specific Models:

YFZ450, YFZ450S

Total Pages:

355

Type:

Official Factory Service / Repair Manual

Primary Language:

English

File Format:

PDF

Delivery Format:

PDF Instant Download

📖 Manual Coverage

Engine:

Complete engine overhaul, disassembly, assembly, tuning, performance modifications (carburetor, ignition timing), internal component replacement (pistons, rings, rods, crankshaft, valve train, oil pump).

Fuel System:

Carburetor assembly and tuning, fuel pump, fuel filter, fuel lines, fuel tank.

Ignition System:

Ignition system troubleshooting, spark plugs, spark plug wires, ignition coil, CDI unit, timing.

Transmission:

Gearbox disassembly, assembly, maintenance, fluid changes, clutch assembly, pressure plate, clutch shoes.

Brakes:

Brake system maintenance, brake pad replacement, brake shoe replacement, rotor replacement, brake fluid changes, hydraulic lines, caliper overhaul.

Suspension:

Front and rear suspension system diagnostics, adjustments, component replacement (shocks, struts, bushings), alignment procedures.

Electrical System:

Wiring harness diagrams, component testing, sensor diagnostics, starter motor, battery maintenance, lighting systems.

Chassis And Bodywork:

Frame inspection, body panel removal/installation, fasteners, seals, trim replacement, mud guards, bumpers.

Cooling System:

Radiator, radiator fan, oil cooling system, coolant hoses, antifreeze specifications.

Maintenance:

Routine maintenance, oil changes, transmission fluid changes, air filter replacement, spark plug replacement, tire rotation, brake maintenance.

Repair:

Complete component repair and replacement for all covered systems, engine rebuilds, transmission overhauls, electrical system diagnostics and repair.

Troubleshooting:

Diagnostic flowcharts, common problem identification and solutions for engine, transmission, electrical, and chassis issues.

Technical Specifications:

Torque specifications for all fasteners, fluid capacities, clearances, compression ratios, timing specifications, electrical resistance values.

Special Tools:

Identification and usage of specialized tools required for specific repair and maintenance procedures (e.g., rotor puller, specialized wrenches).

Depth:

Comprehensive from basic DIY maintenance to full workshop-level mechanical and electrical repair, including engine and transmission rebuilds.

📊 Manual Specifications

Quality:

Factory Quality

Searchability:

Keyword Searchable

Printable:

Yes

Zoom Functionality:

Yes

Type:

Digital (PDF Download)

Type:

Not Applicable (Digital)

⚙️ Engine Specifications

Type:

4-Stroke, DOHC, 5-Valve, Liquid-Cooled Single Cylinder

Displacement:

449cc

Bore X Stroke:

95.0 mm x 63.1 mm

Compression Ratio:

11.2:1 (Typical for the era, refer to manual for exact spec)

Horsepower:

Approx. 50-55 HP (Varies by year and tuning, refer to manual for specifics)

Torque:

Refer to manual for specific torque figures

Carburetor:

Keihin FCR39 Flat-Slide Carburetor (or similar, model-specific)

Fuel Type:

Unleaded Gasoline, Octane Rating 91 or higher recommended

Oil Type:

Yamalube Performance 4 (or equivalent API SG, JASO MA rated 10W-40 or 20W-50, refer to manual for precise specification)

Ignition System:

Digital TCI (Transistor Controlled Ignition)

🔧 Transmission

Type:

5-Speed Manual with Reverse

Type:

N/A

Clutch Type:

Wet, Multi-Disc Clutch

Final Drive:

O-ring sealed chain

Oil Type:

Yamalube 4 (or equivalent API SG, JASO MA rated 10W-40 or 20W-50, refer to manual for precise specification)

📐 Dimensions

Length:

Approx. 70.3 inches (1785 mm)

Width:

Approx. 45.7 inches (1160 mm)

Height:

Approx. 41.1 inches (1045 mm)

Dry Weight:

Approx. 357 lbs (162 kg)

Fuel Capacity:

Approx. 2.6 gallons (9.8 L)

Measurement:

Approx. 49.2 inches (1250 mm)

Measurement:

Approx. 4.4 inches (112 mm)

🛡️ Safety Features

Classification:

N/A (Not typically rated by NHTSA or IIHS as it's an off-road vehicle)

Brakes:

Hydraulic Disc Brakes (Front and Rear)

Throttle Limiter:

Refer to manual for any governor or throttle limiting features

Handlebars:

ATV-specific handlebars with safety features

Footwells:

Wide, serrated footwells for grip and protection.

💡 Technology Features

System:

N/A (Focus on performance, no infotainment features)

Features:

N/A

Features:

N/A

🔧 Maintenance

Oil Change:

Every 20-30 operating hours or annually, refer to manual for exact interval.

Air Filter Cleaning:

Frequent inspection and cleaning based on operating conditions, refer to manual.

Spark Plug Replacement:

Refer to manual for specific mileage or hour interval.

Engine Oil:

Yamalube Performance 4 (or equivalent API SG, JASO MA rated 10W-40 or 20W-50, refer to manual for precise specification)

Transmission Oil:

Yamalube 4 (or equivalent API SG, JASO MA rated 10W-40 or 20W-50, refer to manual for precise specification)

Coolant:

Permanent type antifreeze coolant (50/50 mixture with distilled water), refer to manual for specific Yamaha coolant part number if applicable.

Camshaft Wear:

Some early models experienced camshaft wear; manual provides inspection and replacement procedures.

Carburetor Tuning:

Sensitivity to altitude and temperature changes requires proper tuning; manual covers detailed carburetor adjustment.

Clutch Engagement:

Proper clutch adjustment and maintenance are crucial for performance and longevity; manual details these procedures.

📚 Vehicle History

Manufacturer:

Yamaha Motor Company, known for performance and innovation in powersports.

Introduction Year:

2003

Key Innovations:

Introduction of the 450cc 5-valve engine, lightweight chassis design, and aggressive styling that set a new standard in its class.

Manufacturing Location:

Japan (primary, refer to manual for specific chassis VIN details)

🏆 Awards & Recognition

Industry Impact:

Widely regarded as a benchmark in the sport ATV segment for its performance and handling.