The Big Bear 400, produced from 2000 to 2004, is a robust and dependable all-terrain vehicle designed for both demanding work and recreational trail riding. Known for its comfortable ride and capable performance, this model features independent front suspension, an automatic transmission, and a reliable air-cooled engine. Its durable construction, coupled with significant towing and carrying capacity, makes it a practical choice for various utility tasks. The Big Bear 400 (YFM400F for 4x4 and YFM400 for 4x2 chassis codes) embodies a commitment to building high-quality, user-friendly powersports equipment. This comprehensive workshop service repair manual provides extensive guidance for the Big Bear 400. It covers all essential aspects of maintenance, repair, troubleshooting, and diagnostics, including detailed procedures for the engine, transmission, chassis, brakes, and electrical systems. With factory-level detail, torque specifications, and step-by-step instructions, this manual is an indispensable resource for owners, mechanics, and technicians seeking to maintain the optimal performance and longevity of their vehicle. The manual includes wiring diagrams, exploded views, and assembly/disassembly procedures to facilitate efficient and accurate servicing. 🏷️ Basic Information Identification Make: Yamaha Model: Big Bear 400 Model Years Covered: 2000, 2001, 2002, 2003, 2004 Codes Chassis Codes: YFM400F (4x4), YFM400 (4x2) 👋 Introduction Market Position Positioning: The Yamaha Big Bear 400 was positioned as a rugged, reliable utility ATV for work and recreational trail riding, known for its comfort and capability. Competitive Analysis Competitors: Competed with models like the Honda Foreman 400/450, Suzuki Vinson 500, and Kawasaki Prairie 360/400. Key Features Features: Independent front suspension (IFS), automatic transmission, reliable single-cylinder engine, durable build quality, excellent towing and carrying capacity. Value Proposition Manual Value: This workshop manual provides essential information for maintaining the longevity and performance of the Yamaha Big Bear 400, covering all critical repair and service procedures. 📋 Manual Details Coverage Areas Primary Coverage: Complete Service, Repair, Maintenance, Troubleshooting, Diagnostics Secondary Coverage: Wiring Diagrams, Specifications, Exploded Views, Assembly/Disassembly Procedures Page Count Estimated Page Count: Hundreds of pages (specific count not provided, but indicative of comprehensive coverage) Manual Type Type: Workshop Service Repair Manual Language Language: English Format Format: PDF Download 📖 Manual Coverage Systems Covered Engine: Complete overhaul, inspection, tuning, carburetor, cooling system, lubrication Transmission: Clutch, gearbox, final drive, drive shafts, differential (where applicable) Chassis: Frame, suspension (front and rear), steering, wheels, tires Brakes: Hydraulic system, calipers, master cylinder, brake lines, parking brake Electrical: Ignition system, lighting, starting system, charging system, battery, wiring diagrams Bodywork: Body panels, fenders, racks, seat, plastics Procedures Included Maintenance: Oil changes, filter replacements, spark plug service, valve adjustments, lubrication points Repair: Engine rebuilds, transmission repairs, suspension component replacement, brake system overhaul Troubleshooting: Diagnostic flowcharts, fault finding for engine, electrical, and mechanical issues Diagnostics: Component testing, electrical system diagnosis, performance checks Technical Depth Depth: Comprehensive factory-level detail, suitable for professional technicians and advanced DIY users Detail Level: Includes step-by-step instructions, torque specifications, clearances, and special tool requirements 📊 Manual Specifications File Format Format: PDF Searchability: Likely text-searchable within the PDF Print Quality Printability: Designed for printing individual pages or sections as needed Binding Type Binding Type: N/A (Digital Download) Paper Type Paper Type: N/A (Digital Download) ⚙️ Engine Specifications Primary Engine Engine Type: 4-stroke, SOHC, air-cooled Displacement: 386cc Bore X Stroke: 83 mm x 71 mm Compression Ratio: 8.6:1 Performance Horsepower: Approx. 20-22 HP (at crankshaft, estimated) Torque: Approx. 22-24 lb-ft (at crankshaft, estimated) Fuel System Fuel Delivery: Carburetor (Mikuni BSR33) Fuel Type: Unleaded gasoline, 87 octane minimum Ignition Ignition System: CDI (Capacitor Discharge Ignition) Lubrication Oil Type: Yamalube 4 (or equivalent API SE, SF, SG, SH, SJ or higher, SAE 10W-40 or 20W-50) Oil Capacity W Filter: 2.20 Liters (2.32 US qt) Cooling System Cooling Method: Air-cooled with oil cooler 🔧 Transmission Standard Type: Automatic (Yamaha Ultramatic®) Drive System: Shaft drive (2WD/4WD selectable) Features Gear Selection: High, Low, Neutral, Reverse, Park Fluid Specifications Transmission Fluid: Yamalube SAE 10W-30 API SF (or equivalent) Transmission Fluid Capacity: 0.70 Liters (0.74 US qt) 📐 Dimensions Exterior Length: 2000mm (78.7 in) Width: 1120mm (44.1 in) Height: 1150mm (45.3 in) Wheelbase: 1260mm (49.6 in) Ground Clearance: 235mm (9.3 in) Weights Dry Weight: 253 kg (558 lbs) for 4x4 Curb Weight: 277 kg (611 lbs) for 4x4 (approx.) Cargo Front Rack Capacity: 90 kg (200 lbs) Rear Rack Capacity: 180 kg (400 lbs) Towing Capacity: 500 kg (1102 lbs) Wheels And Tires Front Tire Size: AT25x8-12 Rear Tire Size: AT25x10-12 Wheel Bolt Pattern: 4-stud, 110mm PCD (typical for Yamaha ATVs) 🛡️ Safety Features Ratings Atv Safety Standards: Designed and manufactured to meet current ANSI/SVIA safety standards. Active Features Selectable 4Wd: Provides enhanced traction for challenging terrain. Engine Braking: Ultramatic transmission provides inherent engine braking for descents. Passive Features Lighting: Dual 30W halogen headlights, 15W taillight/stoplight. Ergonomics: Comfortable seat and handlebar positioning for rider control. 💡 Technology Features Infotainment Infotainment System: N/A (Utility ATV) Driver Assistance...