The Big Bear 400, model code YFM400, is an All-Terrain Vehicle (ATV) designed for utility and rugged off-road performance. Produced for the model years 2000 through 2003, this ATV is powered by a 386cc air-cooled, 4-stroke engine, delivering approximately 21 horsepower and 23.3 lb-ft of torque, coupled with an automatic YCCT transmission. Known for its reliable engineering and capability, the Big Bear 400 features hydraulic disc brakes for effective stopping power and offers both 2WD and 4WD selectable drive systems. Its robust design includes a durable chassis and suspension, making it suitable for a variety of demanding tasks and terrains. This comprehensive workshop repair service manual provides complete coverage for the Big Bear 400, encompassing repair, service, maintenance, restoration, rebuilding, and diagnostics for both 2WD and 4x4 models. The manual details procedures for all major systems, including the engine, fuel system, ignition, cooling, transmission, drivetrain, suspension, steering, braking, and electrical systems. It also covers routine and scheduled maintenance, in-depth troubleshooting guides, and technical specifications such as torque values and fluid capacities. Illustrated with clear diagrams and step-by-step instructions, this manual is an essential resource for DIY owners, home mechanics, and professional technicians seeking to maintain and repair their vehicle. 🏷️ Basic Information Identification Make: Yamaha Model: Big Bear 400 Model Code: YFM400 Chassis Code: YFM400 Vehicle Type: All-Terrain Vehicle (ATV) Applicable Years: 2000, 2001, 2002, 2003 👋 Introduction Market Position Target User: DIY owners, home mechanics, professional technicians, workshops Competitive Analysis Manual Advantage: Comprehensive, detailed, and up-to-date for specific model years, offering professional-level guidance Key Features Feature Highlight: Instant download access post-purchase 📋 Manual Details Coverage Areas Manual Scope: Complete repair, service, maintenance, restoration, rebuilding, and diagnostics Drive Types Covered: 2WD and 4x4 models Page Count Page Count: 425 Manual Type Manual Type: Workshop Repair Service Manual Original Equipment Manufacturer Compliance: Yes (Equivalent to factory manual used by professionals) Language Language: English Format File Format: PDF Download Distribution Method: Digital Download (Instant Access after Payment) 📖 Manual Coverage Systems Covered Engine: Complete engine overhaul, including disassembly, inspection, repair, and reassembly Fuel System: Carburetor service, fuel pump, fuel lines, fuel tank maintenance Ignition System: Ignition coil, CDI unit, spark plug service, timing adjustments Cooling System: Radiator, fan, coolant, hoses, thermostat service Transmission Drive System: Operation, maintenance, and repair of the transmission, clutch, and drive components (including 4WD system) Drivetrain: Axles, differentials, CV joints, driveshafts Suspension System: Front and rear suspension components, shock absorbers, bushings, A-arms Steering System: Steering column, tie rods, steering knuckle, wheel alignment Braking System: Hydraulic brake system, calipers, master cylinder, brake lines, pads, rotors Electrical System: Wiring diagrams, lighting, battery, starter, alternator, fuses, switches, sensors Chassis Frame: Frame inspection and repair Bodywork: Body panel removal and installation, fenders, racks Procedures Included Routine Maintenance: Oil changes, filter replacements, lubrication, tire pressure checks Scheduled Maintenance: Recommended service intervals for various components Troubleshooting: Diagnostic procedures for common and uncommon problems, fault finding guides Repair Procedures: Detailed step-by-step instructions for component repair and replacement Rebuild Procedures: Complete teardown and rebuild instructions for major components like the engine and transmission Technical Specifications: Torque specifications, clearances, fluid capacities, electrical values Technical Depth Depth Of Information: Comprehensive, covering all aspects from basic maintenance to complete engine and drivetrain overhauls Illustrations Illustration Quality: Illustrated with clear step-by-step instructions and images Diagrams: Includes part diagrams for component identification and assembly 📊 Manual Specifications File Format File Type: PDF Searchability: Likely text-searchable PDF (common for quality manuals) Print Quality Printability: Printable on any standard printer Binding Type Binding Type: N/A (Digital Download) Paper Type Paper Type: N/A (Digital Download) File Size File Size Range: Up to 2550 MB (indicates high detail and image content) ⚙️ Engine Specifications Primary Engine Engine Type: 4-stroke, SOHC, air-cooled Engine Displacement: 386 cc Bore X Stroke: 83.0 mm x 71.5 mm Compression Ratio: 9.2:1 Performance Horsepower: Approx. 21 hp @ 5500 rpm (Varies slightly by year) Torque: Approx. 23.3 lb-ft @ 4500 rpm (Varies slightly by year) Fuel System Fuel Delivery: Mikuni BSR33 carburetor Fuel Type: Unleaded gasoline Ignition System Ignition Type: CDI (Capacitor Discharge Ignition) Cooling System Cooling Method: Air-cooled 🔧 Transmission Standard Transmission Type: Automatic (Yamaha Constant-Velocity Transmission - YCCT) Gear Selection: High, Low, Neutral, Reverse Features Drive System: Shaft drive (2WD or 4WD selectable) Final Drive: Sealed O-ring chain and sprockets (rear), driveshaft (front) 📐 Dimensions Exterior Length: 77.0 inches (1955 mm) Width: 44.3 inches (1125 mm) Height: 43.1 inches (1095 mm) Wheelbase: 50.4 inches (1280 mm) Ground Clearance: Approx. 10.2 inches (260 mm) Weights Dry Weight: Approx. 503 lbs (228 kg) Fuel Capacity: 3.2 gallons (12 liters) including 0.8-gallon reserve 🛡️ Safety Features Ratings Safety Design Focus: Off-road stability and rider control Active Features Braking System Type: Hydraulic disc brakes (front and rear) Parking Brake: Mechanical drum brake (rear, lever-actuated) Passive Features Lighting: Dual 30W headlights, 5W taillight/brake light...