This workshop service repair manual covers the YFM450FA Grizzly 450 4x4 Automatic Transmission model, produced between 2003 and 2006. Known for its robust single-cylinder engine and the intuitive On-Command 4WD system, the Grizzly 450 is a capable mid-size utility ATV designed for off-road enthusiasts, farmers, and recreational riders. Its engineering emphasizes reliability and durability, offering a balance of power and comfort for demanding terrains. Key features include an automatic Ultramatic transmission for smooth power delivery and strong engine braking, hydraulic disc brakes for effective stopping, and a digital LCD meter providing essential operational information. This comprehensive manual is your essential guide for maintaining and repairing the YFM450FA Grizzly 450. It details all aspects of the vehicle, from complete engine teardown and rebuild procedures to specific maintenance tasks like oil changes, filter replacements, and valve adjustments. You will find step-by-step instructions for servicing the fuel, cooling, ignition, transmission, drivetrain, suspension, steering, and electrical systems, along with detailed troubleshooting guides, torque specifications, and wiring diagrams. This resource is designed to empower owners and technicians to keep the Grizzly 450 in optimal condition, ensuring its longevity and performance. 🏷️ Basic Information Identification Make: Yamaha Model: YFM450FA Model Trim: Grizzly 450 4x4 Model Nickname: Grizzly 450 Generation Generation Code: First Generation Codes Chassis Code: 4WD Automatic Transmission 👋 Introduction Market Position Vehicle Segment: Mid-size 4x4 Utility ATV Target Audience: Off-road enthusiasts, farmers, hunters, recreational riders requiring 4WD capability Competitive Analysis Key Competitors: Honda FourTrax Foreman, Suzuki King Quad, Polaris Sportsman Key Features Engine Type: Compact and reliable single-cylinder engine Drivetrain Features: On-Command 4WD system for easy engagement Transmission Type: Automatic transmission with Ultramatic system for smooth power delivery Manual Benefit Value Proposition: Enables owners to perform all necessary maintenance and repairs, reducing reliance on dealerships and saving costs. 📋 Manual Details Coverage Areas Coverage Years: 2003, 2004, 2005, 2006 Model Variants Covered: YFM450FA (4x4 Automatic) Page Count Estimated Pages: Hundreds of pages (specific count not provided, but indicative of comprehensive coverage) Manual Type Manual Type: Workshop Service Repair Manual Manual Source: Official Factory Service Manual Language Language: English Format Format: PDF Download 📖 Manual Coverage Systems Covered Engine: Complete engine teardown, assembly, inspection, and repair (including top-end and bottom-end) Fuel System: Carburetor service, fuel pump, fuel lines, fuel tank maintenance Cooling System: Radiator, fan, thermostat, coolant specifications and bleeding procedures Ignition System: CDI unit, ignition coil, spark plug specifications and testing Transmission: Automatic transmission (AT) service, lubrication, torque converter, internal components Drivetrain: Shaft drive, differential, CV joints, driveshaft inspection and repair Suspension: Front and rear suspension components, shock absorbers, A-arms, bushings Steering: Steering column, tie rods, knuckle inspection and adjustment Brakes: Hydraulic brake system, caliper service, master cylinder, brake pads, brake fluid specifications Electrical System: Wiring diagrams, battery service, starter motor, alternator, lighting system, fuses, relays Chassis Frame: Frame inspection, welding points, component mounting Bodywork: Body panel removal and installation, plastic components, fenders, racks Wheels Tires: Wheel bearing inspection, tire pressure recommendations, wheel removal/installation Procedures Included Maintenance: Oil changes, filter replacements, lubrication points, valve adjustments, spark plug replacement Troubleshooting: Diagnostic charts for common problems, fault finding procedures, electrical system diagnostics Repair: Step-by-step instructions for all major component repairs and replacements Assembly Disassembly: Detailed procedures for complete teardown and reassembly of all major systems Torque Specifications: Precise torque values for all critical fasteners Wiring Diagrams: Comprehensive electrical schematics for all model variations Technical Depth Depth Level: Complete overhaul and rebuild procedures, including specialized tools and measurements Diagnostic Capabilities: In-depth troubleshooting guides for identifying and resolving mechanical and electrical issues 📊 Manual Specifications File Format File Type: PDF (Portable Document Format) Searchability: Likely text-searchable due to being a factory manual Print Quality Print Recommendation: Printable in its entirety or selected sections Binding Type Binding Options: Not applicable for PDF download; intended for digital use or self-printing and binding Paper Type Paper Recommendation: N/A (digital format) ⚙️ Engine Specifications Primary Engine Engine Type: 4-stroke, SOHC, air-cooled, single-cylinder Displacement: 421 cc Bore X Stroke: 95.0 mm x 60.1 mm Compression Ratio: 9.2:1 Valve Arrangement: SOHC (Single Overhead Camshaft) Carburetor Model: Mikuni BSR33/1 Ignition Type: DC-CDI (Direct Current Capacitor Discharge Ignition) Starter System: Electric Starter Performance Horsepower Estimate: Approx. 22-25 HP (manufacturer does not typically publish specific HP figures for ATVs) Torque Estimate: N/A (manufacturer does not typically publish specific torque figures for ATVs) Fuel System Fuel Type: Unleaded gasoline Fuel Tank Capacity: 3.7 gallons (14 L) 🔧 Transmission Standard Transmission Type: Automatic (CVT - Continuously Variable Transmission) with Ultramatic system Drive System: Shaft Drive, 4WD Optional Gear Selection: High, Low, Neutral, Reverse Features Engine Braking: Features strong engine braking due to CVT design Drive Engagement: On-Command 2WD/4WD selection Fluid Specifications Transmission Fluid Type: Yamaha's recommended gear oil (specific part number available in manual, e.g., Yamalube) 📐 Dimensions Exterior Overall Length: 76.8 in (1,950 mm) Overall Width: 41.5 in...