This manual covers SX, MXC, and EXC Racing motorcycles manufactured between 2000 and 2004, including variants such as the 250, 400, 520, and 525cc models. These high-performance off-road machines are renowned for their powerful engines, advanced WP suspension, and robust build quality, making them a top choice for professional racers and serious enthusiasts. KTM's strong heritage in off-road competition is reflected in the design and engineering of these models, which offer exceptional performance and reliability in demanding conditions. This comprehensive Workshop Service Repair Manual provides detailed procedures for all aspects of maintenance, troubleshooting, and repair. It covers essential systems including the engine, cooling, fuel, ignition, transmission, suspension, brakes, and electrical systems. The manual includes scheduled maintenance tasks, diagnostic guides for common issues, and in-depth instructions for engine and transmission rebuilds. With OEM-equivalent accuracy, this English language manual is an indispensable resource for owners and technicians aiming to maintain the peak performance and longevity of their off-road motorcycles. 🏷️ Basic Information Identification Make: KTM Model: SX, MXC, EXC Racing Model Variants: 250, 400, 520, 525 Year Range: 2000, 2001, 2002, 2003, 2004 Codes Manual Code Prefix: Likely starts with '8000...' 👋 Introduction Market Position Segment: High-performance off-road motorcycles (Motocross, Enduro, Supercross) Target Audience: Professional racers, serious amateur riders, mechanics, and KTM enthusiasts. Competitive Analysis Competitors: Yamaha YZ, Honda CRF/CR, Suzuki RM/RM-Z, Kawasaki KX/KX-F. Unique Selling Points: KTM's reputation for powerful engines, advanced WP suspension, and robust build quality for demanding off-road use. Key Features Manual Benefit: Provides essential information for maintaining peak performance and longevity of these competitive machines. Manual Accuracy: OEM equivalent ensures factory-correct procedures and specifications. 📋 Manual Details Coverage Areas Primary Coverage: Workshop Service Repair Secondary Coverage: Maintenance, Troubleshooting, Diagnostics, Rebuilds Page Count Estimated Pages: Likely 300-600 pages (typical for comprehensive service manuals) Manual Type Type: Workshop Service Repair Manual Language Language: English Format Format: Downloadable PDF 📖 Manual Coverage Systems Covered Engine: Comprehensive engine disassembly, inspection, assembly, tuning, and repair for all listed displacements. Cooling System: Radiator, coolant flow, fan operation, thermostat, and related components. Fuel System: Carburetor(s) (Mikuni VM series likely), fuel pump, fuel lines, fuel tank inspection and cleaning. Ignition System: CDI unit, spark plug, ignition coil, wiring, timing specifications. Transmission: Clutch operation, gearbox disassembly, inspection, assembly, gear selection, and lubrication. Suspension: Front forks (WP USD likely) - disassembly, seal replacement, oil levels and types, damping adjustments. Rear shock absorber - servicing, spring preload, damping adjustments. Brakes: Hydraulic brake systems (front and rear), caliper service, pad replacement, fluid type (DOT 4 likely), bleeding procedures. Electrical System: Wiring diagrams, battery maintenance, lighting, starter motor, charging system, fuses, switches. Chassis: Frame inspection, steering head bearing service, wheel bearing replacement, spoke tensioning. Bodywork: Fairing removal and installation, seat, fuel tank cover, fenders. Procedures Included Scheduled Maintenance: Oil changes, filter replacements, chain lubrication and adjustment, spark plug checks, valve clearance adjustments. Troubleshooting: Diagnostic charts for common problems, symptom-based troubleshooting guides. Engine Repair: Top-end rebuilds (piston, rings, cylinder), bottom-end rebuilds (crankshaft, bearings), timing chain replacement. Transmission Repair: Gearbox disassembly and reassembly, clutch plate replacement. Suspension Servicing: Fork seal replacement, fork oil change, rear shock absorber rebuild. Brake System Maintenance: Brake bleeding, caliper piston service, fluid replacement. Electrical Diagnostics: Wiring harness troubleshooting, component testing. Technical Depth Depth: Comprehensive, suitable for professional mechanics and experienced DIY enthusiasts. Diagnostic Level: Includes detailed diagnostic flowcharts and component testing procedures. Rebuild Level: Covers complete engine and transmission rebuilds, including specifications and torque values. 📊 Manual Specifications File Format File Type: PDF Searchability: Likely text-searchable PDF, allowing quick access to information. Print Quality Image Resolution: Expect clear diagrams and high-resolution images suitable for printing. Binding Type Binding: N/A (Digital PDF) Paper Type Paper Quality: N/A (Digital PDF) ⚙️ Engine Specifications Primary Engine Configuration: Single-cylinder, four-stroke (typically SOHC or DOHC depending on specific model year and variant). Displacement 250: 250cc (Approximate) Displacement 400: 400cc (Approximate) Displacement 520: 520cc (Approximate) Displacement 525: 525cc (Approximate) Cooling: Liquid-cooled Starting System: Kick-start (likely primary, some models might have electric start option but less common for this era SX/MXC). Performance Horsepower 250: Estimated 35-45 HP (Varies by model and tuning) Horsepower 525: Estimated 50-60 HP (Varies by model and tuning) Torque Curve: Broad and torquey, characteristic of KTM's off-road focused engines. Fuel System Carburetor Type: Mikuni VM Series (e.g., VM38 or VM40 likely for larger displacements). Fuel Type: Unleaded gasoline (Octane rating specified in manual, typically 91+). Fluid Specifications Engine Oil Type: High-quality motorcycle-specific 4-stroke engine oil (e.g., Motorex or equivalent, SAE 10W/40 or 15W/50 depending on temperature). Engine Oil Capacity: Approximately 0.8 - 1.2 liters (refer to manual for exact capacity by model). Coolant Type: Ethylene glycol-based coolant (50/50 mix with distilled water recommended). 🔧 Transmission Standard Type: Constant mesh, sequential manual gearbox. Number Of Gears: Typically 5 or 6 speeds (manual will specify for each model variant). Optional Optional Features:...