The Yamaha YFM660FS Grizzly, a first-generation model produced from 2002 to 2005, stands as a formidable All-Terrain Vehicle (ATV) engineered for demanding off-road conditions. Featuring a powerful 660cc, 5-valve SOHC liquid-cooled engine paired with its renowned automatic transmission and 2WD/4WD system, this ATV delivers exceptional performance and terrain adaptability. Its independent front and rear suspension, coupled with sealed hydraulic disc brakes, ensures a comfortable and controlled ride across varied landscapes, making it a reliable choice for outdoor enthusiasts, hunters, and farmers. This comprehensive workshop service manual is designed to provide detailed guidance for the maintenance, repair, and overhaul of the Yamaha YFM660FS Grizzly from 2002 to 2005. Covering all essential systems including the engine, transmission, chassis, suspension, brakes, and electrical components, this manual offers step-by-step instructions, diagnostic procedures, and technical specifications. It serves as an indispensable resource for owners and technicians to ensure the optimal performance, longevity, and safety of the vehicle through accurate and thorough information. 🏷️ Basic Information Identification Make: Yamaha Model: YFM660FS Grizzly Model Designation: FS (Four-Stroke, SOHC) Generation Generation Designation: First Generation Grizzly 660 Codes Chassis Code: YFM660FS 👋 Introduction Market Position Category: High-performance All-Terrain Vehicle (ATV) Target Audience: Outdoor enthusiasts, hunters, farmers, recreational riders requiring a robust and capable off-road machine. Competitive Analysis Competitors: Honda Foreman, Suzuki King Quad, Polaris Sportsman, Kawasaki Prairie. Key Features Engine Type: Liquid-cooled, 4-stroke, SOHC, 5-valve, single-cylinder Drive System: Ultramatic automatic transmission with On-Command 2WD/4WD and differential lock. Suspension: Independent front and rear suspension for superior ride comfort and terrain handling. Braking: Sealed hydraulic disc brakes front and rear. 📋 Manual Details Coverage Areas Years Covered: 2002, 2003, 2004, 2005 Page Count Total Pages: 508 Manual Type Manual Type: Workshop Service Manual / Repair Manual Language Language: English Format File Format: PDF 📖 Manual Coverage Systems Covered Engine: Complete overhaul, maintenance, diagnostics, cooling system, lubrication system, fuel system, ignition system, exhaust system, carburetor adjustment and overhaul, internal engine components (piston, rings, crankshaft, cylinder head, valves). Transmission: Automatic transmission (CVT), clutch operation, belt inspection and replacement, gearbox maintenance, final drive system, differential. Chassis And Suspension: Frame inspection, front and rear suspension systems (shocks, springs, A-arms), steering system (handlebars, tie rods, rack and pinion), wheel bearings, lubrication points. Brakes: Hydraulic brake system, front and rear brake calipers, brake discs, brake pads, brake fluid specifications and bleeding procedures, parking brake system. Electrical System: Wiring diagrams, battery maintenance, starter motor, charging system (stator, regulator/rectifier), lighting system (headlights, taillights, indicators), ignition system components, switches, sensors, fuses, troubleshooting electrical faults. Bodywork And Controls: Body panel removal and installation, seat, fenders, racks, controls (throttle, brake levers, shifter), cable adjustments, fluid reservoirs. Procedures Included Maintenance: Scheduled maintenance intervals, oil and filter changes, air filter cleaning/replacement, spark plug replacement, valve clearance adjustment, drive belt inspection, lubrication. Troubleshooting: Systematic diagnostic procedures for common and uncommon issues, fault codes (if applicable), diagnostic flowcharts. Repair: Detailed step-by-step instructions for disassembly, repair, and reassembly of all major components and systems. Overhaul: Comprehensive guidance for complete engine, transmission, and major component rebuilds. Technical Depth Depth: Comprehensive, covering everything from basic rider maintenance to complete engine and transmission rebuilds. Includes detailed torque specifications, clearances, and diagnostic procedures. 📊 Manual Specifications File Format File Format Detail: Searchable PDF for efficient information retrieval, printable pages. Print Quality Image Resolution: High resolution for clear diagrams and text. Binding Type Binding Type: N/A (Digital PDF download) Paper Type Paper Type: N/A (Digital PDF download) ⚙️ Engine Specifications Primary Engine Engine Type: 5-valve SOHC, single cylinder, liquid-cooled, 4-stroke Displacement: 660 cc Bore X Stroke: 95.0 mm x 93.2 mm Compression Ratio: 9.2:1 Performance Horsepower Estimate: Approximately 45-50 HP (varies by region and tuning) Torque Estimate: Approximately 40-45 ft-lbs (varies by region and tuning) Fuel System Carburetor: Mikuni BSR42 (single) Fuel Type: Unleaded gasoline (minimum 87 octane) Lubrication System Oil Type: Yamaha Genuine 4-stroke motor oil or equivalent SAE 10W-40 API SG or higher. Oil Capacity: 2.40 L (2.54 US qt) without filter change, 2.50 L (2.64 US qt) with filter change. Cooling System Coolant Type: Ethylene glycol based antifreeze mixed 50/50 with distilled water. Coolant Capacity: 1.90 L (2.01 US qt) 🔧 Transmission Standard Transmission Type: Yamaha Ultramatic V-belt automatic transmission Drive Modes: 2WD, 4WD, 4WD with differential lock (On-Command system) Optional Optional Transmissions: N/A (All models equipped with Ultramatic CVT) Features Features: Engine braking control, automatic centrifugal clutch, durable V-belt system. Maintenance Drive Belt Inspection Interval: Every 1,000 km or 6 months, whichever comes first. Gear Oil Type: Yamalube Gear Oil or equivalent SAE 80 API GL-4. Gear Oil Capacity: 0.25 L (0.26 US qt) 📐 Dimensions Exterior Overall Length: 2,003 mm (78.9 in) Overall Width: 1,079 mm (42.5 in) Overall Height: 1,067 mm (42.0 in) Wheelbase: 1,231 mm (48.5 in) Ground Clearance: 260 mm (10.2 in) Weights Wet Weight: 272 kg (599.7 lbs) Fuel Capacity: 17 L (4.5...