This manual covers the 400 SX, 450 SX, 400 MXC, 450 MXC, 400 XC, and 450 XC models manufactured between 2000 and 2007. These high-performance off-road motorcycles, powered by the robust LC4 engine family, are renowned for their potent performance, capable suspension, and aggressive design, making them suitable for motocross, cross-country, and enduro racing. The legacy in off-road competition is reflected in the engineering quality and durability of these machines, which have earned numerous accolades. This comprehensive factory service and repair workshop manual provides in-depth guidance for owners and technicians. It details essential maintenance procedures, from routine checks and fluid changes to critical component adjustments and rebuilds. The manual covers all major systems, including the engine, transmission, chassis, suspension, brakes, and electrical systems, offering step-by-step instructions, troubleshooting tips, and essential technical specifications. The scope of this manual ensures that users can effectively maintain, diagnose, and repair their motorcycles, maximizing performance and longevity. 🏷️ Basic Information Identification Make: KTM Model: 400 SX, 450 SX, 400 MXC, 450 MXC, 400 XC, 450 XC Model Variants: SX (Motocross), MXC (Cross Country), XC (Cross Country/Enduro) Generation Generation Identifier: 2000-2007 Models Codes Chassis Codes: Likely varied by specific year and model variant, common codes can be found within the manual. Engine Codes: LC4 engine family (various displacements within 400-450cc range) 👋 Introduction Market Position Market Segment: High-performance off-road motorcycles (Motocross, Cross Country, Enduro). Competitive Analysis Competitors: Yamaha YZ/WR series, Honda CR/XR series, Suzuki RM/DR series, Kawasaki KX/KDX series, Husqvarna, Beta. Key Features Vehicle Strengths: Powerful LC4 engines, robust chassis, excellent suspension performance, aggressive styling, capable for demanding off-road competition. Manual Value Proposition Target Audience: KTM owners, aspiring mechanics, off-road enthusiasts looking for in-depth knowledge to maintain and repair their motorcycles. 📋 Manual Details Coverage Areas Countries Of Operation: Global (with potential regional variations noted for emissions/specific components) Page Count Estimated Page Count: Estimated 400-700+ pages (typical for comprehensive service manuals of this era) Manual Type Manual Type: Factory Service & Repair Workshop Manual Language Language: English (primary language expected for download versions of this era) Format Format: Downloadable PDF 📖 Manual Coverage Systems Covered Engine: Complete engine assembly, disassembly, overhaul, tuning, lubrication, cooling system, exhaust system, fuel system, ignition system, starting system. Transmission: Gearbox disassembly, assembly, inspection, lubrication, clutch operation and maintenance, shifting mechanisms. Chassis And Suspension: Frame inspection, fork disassembly and rebuild, rear shock absorber servicing, swingarm, linkage, wheel bearings, steering head bearings. Brakes: Hydraulic brake system diagnosis, caliper servicing, master cylinder overhaul, bleeding procedures, brake pad replacement, rotor inspection. Electrical System: Wiring diagrams, lighting system, ignition coils, battery maintenance, stator and rotor testing, starter motor, fuses, switches, sensors. Fuel System: Carburetor (likely Mikuni or Keihin) disassembly, cleaning, tuning, jetting, fuel pump (if applicable), fuel tank, fuel lines. Bodywork And Ergonomics: Fairings, seat, handlebars, controls, footpegs, fender replacement, graphics/plastics. Procedures Included Maintenance: Routine checks, oil changes, filter replacements, chain adjustment, spark plug replacement, valve clearance adjustment, brake fluid changes, coolant checks. Troubleshooting: Diagnostic charts for common problems, symptoms, and solutions for engine, electrical, and chassis issues. Repair And Rebuild: Detailed step-by-step instructions for component disassembly, inspection, repair, and reassembly of all major vehicle systems. Technical Specifications: Torque values, tolerances, fluid capacities, electrical specifications, diagnostic data. Technical Depth Depth: Comprehensive, covering everything from basic pre-ride checks to full engine and transmission rebuilds. Suitable for professional mechanics and advanced DIY enthusiasts. 📊 Manual Specifications File Format File Format: PDF Print Quality Image Resolution: High-resolution scans, clear diagrams, and readable text. Binding Type Binding Type: N/A (Digital Download) Paper Type Paper Type: N/A (Digital Download) Searchability Searchable Text: Likely includes searchable text for quick information retrieval. Licensing Expiry Dates: No expiry dates Additional Fees: No extra fees ⚙️ Engine Specifications Primary Engine Engine Family: KTM LC4 Single-cylinder, four-stroke Displacement Options: Approximately 400cc and 450cc (specific bore/stroke variations within the model range) Cooling System: Liquid-cooled Valve Train: SOHC (Single Overhead Camshaft), 4 valves Performance Horsepower Range: Estimated 45-55+ hp (depending on specific model and tuning, precise figures in manual) Torque Range: Estimated 35-45+ lb-ft (depending on specific model and tuning, precise figures in manual) Fuel System Carburetor Type: Mikuni (e.g., TM40, TM42) or Keihin FCR (specific model dependent, detailed in manual) Fuel Type: Unleaded gasoline (91-98 octane RON recommended) Ignition System Ignition Type: Electronic ignition (CDI/Digital) 🔧 Transmission Standard Transmission Type: 6-speed manual gearbox Optional Optional Gearbox: N/A (standard 6-speed) Features Clutch Type: Wet multi-plate clutch (hydraulic actuation typical) Gear Ratios: Specific ratios provided within the manual for each model variant. Final Drive: Chain drive 📐 Dimensions Exterior Wheelbase: Varies by model variant and year, typically around 1470-1490 mm (57.9-58.7 inches). Precise figures in manual. Weights Dry Weight: Typically around 110-120 kg (242-265 lbs) without fluids. Specific figures in manual. Fuel Tank Capacity: Approximately 8-10 liters (2.1-2.6 US gallons). Specific figures in manual. 🛡️ Safety Features Ratings Safety...