The Yamaha YFM660 Grizzly, produced from 2001 to 2006, is a powerful all-terrain vehicle (ATV) renowned for its robust build and performance-oriented utility. This ATV segment staple is characterized by its 660cc, 4-stroke, liquid-cooled engine with a 5-valve SOHC design, delivering substantial power and torque for demanding off-road tasks. Notable features include an on-command 2WD/4WD system, a differential lock, and independent rear suspension (IRS), which collectively enhance traction, handling, and rider comfort across varied terrains. The legacy of engineering excellence is evident in the Grizzly's reliability and capability, making it a competitive choice against other leading models in its class. This comprehensive service and repair manual provides detailed guidance for maintaining and repairing the Yamaha YFM660 Grizzly ATV. Covering all aspects from routine scheduled maintenance, such as oil changes and filter replacements, to in-depth component overhauls, this manual is an essential resource. It includes step-by-step procedures for engine, transmission, braking, electrical, and chassis systems, along with troubleshooting guides for common issues. Technicians and owners will find detailed specifications, diagnostic procedures, and high-resolution diagrams invaluable for ensuring the longevity and optimal performance of their vehicle. 🏷️ Basic Information Identification Make: Yamaha Model: YFM660 Grizzly Type: All-Terrain Vehicle (ATV) Codes Chassis Code: YFM660F 👋 Introduction Market Position Segment: Performance-oriented utility ATV segment Competitive Analysis Key Competitors: Honda Foreman, Suzuki King Quad, Polaris Sportsman Key Features Grizzly Identity: Known for its powerful engine, robust build, and independent rear suspension (IRS), offering superior comfort and handling Manual Value Proposition: Provides comprehensive DIY repair and maintenance capabilities, saving owners significant costs associated with dealership service. 📋 Manual Details Coverage Areas Years Covered: 2001, 2002, 2003, 2004, 2005, 2006 Page Count Estimated Pages: Estimated 300-500 pages (typical for comprehensive service manuals) Manual Type Manual Classification: Full Service & Repair Manual Language Language: English Format File Format: PDF Download 📖 Manual Coverage Systems Covered Powertrain: Engine, transmission, drivetrain, clutch, cooling system, fuel system, exhaust system Chassis And Suspension: Frame, suspension (front and rear), steering system, wheels, tires Brakes: Front and rear braking systems (hydraulic, discs, calipers, master cylinders) Electrical: Ignition system, starting system, charging system, lighting, instrumentation, wiring diagrams Bodywork And Trim: Body panels, fenders, plastics, seating, handlebars, guards Procedures Included Maintenance: Scheduled maintenance, oil changes, filter replacements, lubrication, valve adjustments, carburetor tuning Troubleshooting: Diagnostic procedures, common problem identification, symptom-based troubleshooting guides Repair: Engine rebuild, transmission overhaul, suspension repair, brake service, electrical system repairs, component replacement Disassembly And Assembly: Step-by-step instructions for component removal and installation Suspension Setup: Front and rear suspension adjustment procedures, including spring preload and damping settings (if applicable). Wheel Alignment: Specifications and procedures for checking and adjusting front wheel alignment. Cooling System Service: Radiator flushing, coolant replacement, thermostat replacement, and fan operation checks. Drive Shaft And Ujoints: Inspection, lubrication, and replacement procedures for drive shafts and universal joints. Technical Depth Diagnostic Level: Advanced diagnostics, including electrical troubleshooting with wiring diagrams and component testing Rebuild Level: Complete engine and transmission rebuild procedures with detailed specifications and torque values Diagnostic Tools: Information on required special tools and general tools for service and repair 📊 Manual Specifications File Format Searchability: Typically searchable text within the PDF for quick access to information Print Quality Image Clarity: High-resolution diagrams, illustrations, and photographs for clarity Binding Type Digital Binding: PDF format allows for digital navigation via bookmarks and hyperlinks Paper Type Digital Paper Type: N/A (Digital Format) ⚙️ Engine Specifications Primary Engine Engine Type: 4-stroke, SOHC, liquid-cooled, 5-valve, single-cylinder Displacement: 660 cc Bore X Stroke: 100.0 mm x 84.0 mm Compression Ratio: 9.1:1 Performance Horsepower Estimated: Approx. 45-50 HP (varies slightly by year and region) Torque Estimated: Approx. 40-45 lb-ft (varies slightly by year and region) Fuel System Fuel Delivery: Mikuni 41mm BSR carburetor (CV type) Fuel Type: Unleaded gasoline (87 octane recommended) Fuel Tank Capacity: 4.0 US gal (15 L) Lubrication Oil Type: Yamalube 4 (or equivalent) SAE 10W-30 API SG or higher Oil Capacity: 2.5 US qt (2.4 L) with filter change Cooling System Cooling Type: Liquid-cooled Coolant Type: Yamahaitrile/ethylene glycol based coolant (50/50 mix) (Yamalube Super Coolant recommended) 🔧 Transmission Standard Transmission Type: Automatic, V-belt, variable ratio with engine braking Optional Optional Transmission: N/A Features Drive System: 2WD/4WD, shaft drive Differential: Differential lock (on-command) Gear Selection: High (H), Low (L), Neutral (N), Reverse (R), Park (P) Fluid Specifications Transmission Fluid Type: Yamaha Belt Drive Gear Oil (or equivalent SAE 80 hypoid gear oil) 📐 Dimensions Exterior Length: Approx. 81.5 inches (2070 mm) Width: Approx. 43.7 inches (1108 mm) Height: Approx. 45.1 inches (1145 mm) Wheelbase: Approx. 50.4 inches (1280 mm) Weights Dry Weight: Approx. 606 lbs (275 kg) Ground Clearance: Approx. 10.8 inches (275 mm) Cargo Front Rack Capacity: 45 kg (99 lbs) Rear Rack Capacity: 85 kg (187 lbs) Towing Towing Capacity: N/A (refer to owner's manual for specific towing recommendations/limitations) 🛡️ Safety Features Ratings...