This manual covers the 2003 125 SX, 200 SX, 125 MXC, 200 MXC, 125 EXC, and 200 EXC models. These performance-oriented motorcycles are designed for motocross and enduro competition, embodying a legacy of building potent off-road machines. Known for their lightweight construction, agile handling, and aggressive two-stroke power delivery, these models have a history of success in racing. The engineering quality and reliability are hallmarks of Austrian manufacturing, providing riders with competitive edge and durable performance. This comprehensive repair service manual provides in-depth information for professional technicians and experienced DIY mechanics. It covers all essential aspects of maintenance and repair, including detailed engine disassembly and assembly for 125cc and 200cc two-stroke engines, cooling system service, fuel system tuning, ignition system adjustments, transmission and drivetrain maintenance, suspension rebuilds, brake system servicing, and electrical system diagnostics. The manual includes troubleshooting guides, technical specifications, component tolerances, torque values, and identification of special tools, enabling accurate and efficient upkeep of these high-performance off-road motorcycles. 🏷️ Basic Information Identification Make: KTM Model: 125 SX, 200 SX, 125 MXC, 200 MXC, 125 EXC, 200 EXC Year: 2003 Codes Vehicle Segment: Motocross / Enduro Competition 👋 Introduction Market Position Target User: Owners and mechanics of 2003 KTM 125/200 SX, MXC, and EXC models, seeking in-depth repair and maintenance information. Competitive Analysis Manual Advantage: Provides factory-level detail essential for maintaining high-performance off-road motorcycles, bridging the gap between basic owner's manuals and costly dealer-only diagnostics. Key Features Completeness: Comprehensive coverage across multiple performance-oriented models, ensuring wide applicability within the 2003 KTM off-road range. Practicality: Focus on actionable repair and maintenance procedures, with clear illustrations and diagrams. 📋 Manual Details Coverage Areas Manual Type: Repair Service Manual Language: English Format: PDF Download Audience: Professional Technicians and Experienced DIY Mechanics 📖 Manual Coverage Systems Covered Engine: Complete engine disassembly, assembly, inspection, tuning, and troubleshooting for 125cc and 200cc two-stroke engines. Cooling System: Radiator, hoses, water pump, thermostat, and coolant specifications. Fuel System: Carburetor tuning (Mikuni VM series), fuel tank, fuel lines, and filter maintenance. Ignition System: CDI unit, stator, spark plug specifications, coil testing, and timing adjustments. Transmission Drivetrain: Clutch operation and adjustment, gearbox inspection and repair, shift mechanism, and chain/sprocket maintenance. Suspension: Front fork (WP USD) disassembly, seal replacement, oil level and type specifications, rear shock absorber service, linkage lubrication, and adjustment procedures. Brakes: Hydraulic front and rear brake systems, caliper inspection, pad replacement, fluid type (DOT 4), bleeding procedures, and rotor specifications. Electrical System: Wiring diagrams for lighting, kill switch, and basic electrical component testing. Frame Chassis: Frame inspection for cracks, headstock bearing service, swingarm and pivot bearing maintenance. Wheels Tires: Wheel bearing maintenance, spoke tensioning, tire selection and fitting, and pressure recommendations. Procedures Included Routine Maintenance: Pre-ride checks, oil changes (2-stroke premix), air filter cleaning/replacement, chain lubrication, and general bolt torque checks. Engine Overhaul: Piston ring replacement, cylinder head inspection, crankshaft and connecting rod bearing checks, crank seal replacement, and gasket renewal. Suspension Rebuild: Complete fork and shock absorber disassembly, cleaning, reassembly, and charging procedures (where applicable). Carburetor Rebuilding: Jetting recommendations, float level adjustment, idle speed control, and idle mixture settings. Troubleshooting Guides: Diagnosing common starting problems, power loss, overheating, and suspension performance issues. Technical Depth Diagnostic Procedures: Detailed step-by-step procedures for diagnosing mechanical and electrical faults. Component Specifications: Precise measurements for critical engine components (e.g., piston-to-cylinder clearance, ring gap, bearing tolerances). Torque Values: Comprehensive list of torque specifications for all fasteners and critical components. Special Tools: Identification and usage of specialized tools required for certain repairs and adjustments. 📊 Manual Specifications File Format File Type: PDF Searchability: Likely text-searchable PDF (depending on source scan quality). Print Quality Printability: Designed for digital viewing, but printable pages are standard for PDF. Binding Type Binding: N/A (Digital Download) Paper Type Paper Quality: N/A (Digital Download) ⚙️ Engine Specifications Primary Engine Engine Type: Two-stroke, single-cylinder Bore Stroke 125: 54 mm x 54.5 mm (125cc) Bore Stroke 200: 62.5 mm x 65 mm (196cc) Cooling: Liquid-cooled Induction: Carburetor (Mikuni VM 34/38 or similar, depending on model variant) Performance Power Output 125 Est: Approx. 32-35 HP (subject to tuning and specific model) Power Output 200 Est: Approx. 38-42 HP (subject to tuning and specific model) Fuel System Fuel Type: Unleaded gasoline with appropriate 2-stroke oil premix (e.g., 40:1 or 50:1 ratio, check manual for specific recommendations) Carburetor Model: Likely Mikuni VM Series (e.g., VM34 for 125, VM38 for 200, but verify in manual) 🔧 Transmission Standard Transmission Type: 6-speed constant mesh Clutch Type: Wet multi-plate clutch Features Final Drive: Chain drive Gear Ratios: Specific gear ratios are detailed within the manual. Clutch Fluid: Hydraulic fluid specification (refer to manual for type, typically DOT 4). 📐 Dimensions Exterior Frame Type: Chromium-molybdenum steel, central double-tube frame Front Suspension Type: WP USD (Upside Down) forks, adjustable (specific travel varies by model variant) Rear Suspension Type: WP...