The YFM660RNC, also known as the Raptor 660, is a high-performance Sport ATV produced from 2001 to 2006. Engineered with a powerful 660cc liquid-cooled, four-stroke engine and a 5-speed manual transmission with reverse, this model emphasizes robust performance and rider control. Its design philosophy centers on delivering an exhilarating off-road experience, featuring a long-travel independent front suspension and a rear swingarm with a monoshock for superior handling and comfort. The Raptor 660 is equipped with hydraulic disc brakes front and rear and integrated floorboards with heel guards for enhanced rider protection, reflecting a legacy in building reliable and capable ATVs. This comprehensive workshop service manual provides detailed information for the maintenance, repair, and troubleshooting of the YFM660RNC. It covers all essential systems, including engine overhaul, fuel and ignition systems, cooling, transmission, drivetrain, suspension, braking, electrical systems, and chassis components. The manual details routine maintenance procedures, such as oil changes and filter replacements, alongside in-depth guides for major repairs and component disassembly/reassembly. With extensive illustrations, schematics, torque specifications, and diagnostic procedures, this manual serves as an indispensable resource for owners, mechanics, and technicians seeking to preserve the performance and longevity of their Raptor 660. 🏷️ Basic Information Identification Make: Yamaha Model: YFM660RNC Model Nickname: Raptor 660 Vehicle Type: Sport ATV (All-Terrain Vehicle) Codes Manual Product Code: YFM660RNC 👋 Introduction Market Position Vehicle Segment: High-performance sport ATV, competitive in its era. Competitive Analysis Key Competitors: Honda TRX450R, Suzuki LT-Z400, Bombardier DS650. Key Features Engine Type: Liquid-cooled, four-stroke, SOHC, 4-valve, single-cylinder. Transmission Type: 5-speed manual with reverse. Suspension Setup: Long-travel independent front suspension (IFP) and a rear swingarm with a monoshock. Braking System Type: Hydraulic disc brakes front and rear. Design Philosophy: Emphasis on power, handling, and rider comfort for aggressive off-road riding. 📋 Manual Details Coverage Areas Years Covered: 2001, 2002, 2003, 2004, 2005, 2006 Page Count Estimated Page Count: Approximately 400-500 pages (typical for this era of comprehensive service manuals) Manual Type Manual Type: Workshop Service Manual / Repair Manual Language Language: English (standard for most Yamaha service documentation) Format Format: PDF Download 📖 Manual Coverage Systems Covered Engine Overhaul: Complete disassembly, inspection, repair, and reassembly of the engine. Fuel System: Carburetor tuning, cleaning, and overhaul; fuel pump operation; fuel tank and lines. Ignition System: Ignition timing, CDI unit, spark plug specifications, stator and rotor inspection. Cooling System: Radiator, fan, water pump, coolant type and capacity, thermostat. Transmission And Drivetrain: Clutch operation, gearbox disassembly and inspection, chain drive maintenance, final drive assembly. Suspension System: Front and rear suspension geometry, shock absorber overhaul and adjustment, A-arm and linkage maintenance. Braking System: Hydraulic brake system troubleshooting, caliper rebuild, master cylinder service, brake pad replacement, rotor inspection. Electrical System: Wiring diagrams, lighting system, battery maintenance, starter motor, charging system (alternator/stator), fuses, relays. Chassis And Frame: Frame inspection for damage, steering system maintenance, handlebar and control adjustments. Bodywork And Trim: Plastic panel removal and installation, fender and seat maintenance. Procedures Included Routine Maintenance: Oil changes, filter replacements, spark plug checks, air filter cleaning, chain adjustments, pre-ride inspections. Troubleshooting: Diagnosis of common mechanical and electrical issues with step-by-step troubleshooting guides. Major Repairs: Engine rebuilds, transmission overhauls, suspension component replacement, electrical system diagnosis. Component Disassembly Reassembly: Detailed instructions for removing, servicing, and reinstalling all major and minor components. Torque Specifications: Precise torque values for all critical fasteners. Technical Depth Depth Of Coverage: Comprehensive, covering from basic maintenance to complete engine and transmission rebuilds. Diagnostic Capabilities: Includes diagnostic procedures, fault finding charts, and symptom-based troubleshooting. Diagrams And Illustrations: Richly illustrated with exploded views, schematics, and step-by-step diagrams. 📊 Manual Specifications File Format File Type: PDF Print Quality Image Resolution: High-resolution scans suitable for printing individual pages or the entire manual. Binding Type Binding Type For Download: N/A (Digital Download) Paper Type Paper Type For Download: N/A (Digital Document) Searchability Searchable Text: Likely searchable if the PDF is text-based (not purely image-scanned without OCR). ⚙️ Engine Specifications Primary Engine Engine Type: 4-stroke, liquid-cooled, SOHC, 4-valve Displacement: 660 cc Bore X Stroke: 100.0 mm x 84.0 mm Compression Ratio: 9.2:1 Carburetor: Keihin FCR41 (single, flat-slide, with accelerator pump) Performance Horsepower Estimate: Approximately 45-50 HP (stock, at crankshaft) Torque Estimate: Approximately 42-45 lb-ft (stock, at crankshaft) Fuel System Fuel Type: Unleaded gasoline, 87 octane minimum Fuel Capacity: 2.6 gallons (9.8 L) 🔧 Transmission Standard Transmission Type: Constant mesh, 5-speed manual Clutch Type: Wet, multi-plate Reverse Gear: Yes Features Drivetrain: 2WD (Rear Wheel Drive) Final Drive: O-ring sealed chain, 520 Gear Ratios: Detailed in manual, specific ratios for each gear. 📐 Dimensions Exterior Overall Length: 70.9 inches (1800 mm) Overall Width: 47.2 inches (1200 mm) Overall Height: 44.1 inches (1120 mm) Wheelbase: 50.0 inches (1270 mm) Weights Dry Weight: 412 lbs (187 kg) Curb Weight: Approximately 420-430 lbs (depending on fluids) Ground Clearance: 4.4 inches (112 mm) 🛡️ Safety Features Ratings Atv...