This manual covers the 450 SX-F, a high-performance motocross competition motorcycle produced in 2011. Engineered with a liquid-cooled, 4-stroke single-cylinder LC4 engine featuring SOHC and electronic fuel injection, this model is built for demanding off-road racing. It boasts a lightweight chrome-molybdenum steel frame and advanced WP suspension, reflecting KTM's 'Ready to Race' philosophy. The 450 SX-F is renowned for its powerful engine, delivering approximately 56 HP, and its sophisticated chassis design, making it a competitive choice for professional and amateur motocross riders. This comprehensive workshop repair manual provides detailed guidance for the maintenance, repair, and troubleshooting of the 450 SX-F. It covers essential areas including the chassis and engine, with specific sections dedicated to the top and bottom end, lubrication, cooling, ignition, and fuel injection systems. Furthermore, the manual details transmission, suspension, brake, and electrical system servicing, alongside routine maintenance procedures and parts catalog information. With 245 pages of technical information, this manual is an indispensable resource for owners and technicians seeking to ensure the optimal performance and longevity of their competition motorcycle. 🏷️ Basic Information Identification Make: KTM Model: 450 SX-F Year: 2011 Category: Motocross Competition Codes Engine Code Family: LC4 (Single-Cylinder) 👋 Introduction Market Position Segment: Professional Motocross Competition Target User: Professional racers, amateur competitors, and dedicated track day enthusiasts. Competitive Analysis Key Competitors Model Year: Yamaha YZ450F, Honda CRF450R, Kawasaki KX450F, Suzuki RM-Z450 Key Features Engine Type: Liquid-cooled, 4-stroke single-cylinder SOHC Suspension Brand: WP (White Power) Suspension Chassis Design: Lightweight chrome-molybdenum steel frame 📋 Manual Details Coverage Areas Primary Coverage: Chassis and Engine Secondary Coverage: Parts Catalog Information Page Count Total Pages: 245 Manual Type Type: Workshop Repair Manual (Factory Service Manual) Language Language: English (Assumed, based on typical manual content) Format File Type: PDF Interactivity: Active Index and Searchable 📖 Manual Coverage Systems Covered Engine Mechanical: Top end (cylinder, piston, valves), bottom end (crankshaft, connecting rod, bearings), lubrication system, cooling system, ignition system. Engine Fuel Injection: Throttle body, fuel pump, injectors, ECU diagnostics and calibration, airbox and intake tract. Transmission: Clutch (operation, adjustment, replacement), gearbox (gear selection, shifting mechanism), final drive (chain and sprockets). Chassis Suspension: Front forks (WP USD, disassembly, service, damping adjustment, seal replacement), rear shock absorber (WP, linkage system, service, spring preload). Brakes: Front and rear brake systems (calipers, master cylinders, hoses, fluid replacement, bleeding procedures, pad replacement). Electrical System: Battery, starter system, lighting, wiring diagrams, sensor identification and testing, ECU. Frame And Bodywork: Frame inspection, subframe, seat, fuel tank, fenders, plastics, exhaust system mounting. Procedures Included Routine Maintenance: Oil changes, filter replacements, chain adjustment, tire pressure checks, spark plug inspection. Disassembly Assembly: Complete engine teardown and reassembly, suspension fork and shock servicing, wheel bearing replacement, brake system overhaul. Troubleshooting: Diagnostic flowcharts for common starting, running, and performance issues. Error code interpretation. Specifications Settings: Torque values for all fasteners, valve clearance specifications, suspension settings, fluid capacities, and types. Technical Depth Depth: Comprehensive, covering all aspects of maintenance, repair, and diagnosis suitable for experienced mechanics and dedicated DIY enthusiasts. 📊 Manual Specifications File Format PDF Quality: High-resolution, clear text and diagrams, optimized for digital viewing and printing. Print Quality Scalability: Scalable to different screen sizes, zoomable for detailed inspection of diagrams. Binding Type Digital Format: N/A (Digital PDF) Paper Type Digital Format: N/A (Digital PDF) ⚙️ Engine Specifications Primary Engine Engine Type: 4-stroke single-cylinder, liquid-cooled Displacement: 449.3 cc Bore X Stroke: 97 mm x 60.8 mm Valvetrain: SOHC, 4 valves Compression Ratio: 12.3:1 Performance Peak Horsepower: Approx. 56 HP (at crankshaft, varies with tuning) Peak Torque: Approx. 46 Nm (at crankshaft, varies with tuning) Fuel System Fuel Delivery: Electronic Fuel Injection (EFI), Keihin PWK 39 (throttle body) Fuel Type: Unleaded gasoline (95-98 RON recommended) Lubrication System: Semi-dry sump with two oil pumps Oil Type: KTM recommends Motorex Power Synt M 4T SAE 10W-50 Cooling System Type: Liquid-cooled, with electric fan Coolant Capacity: Approx. 0.85 Liters Ignition Type: Digital CDI with variable ignition timing Spark Plug: NGK CR9EKB (or equivalent) 🔧 Transmission Standard Type: 5-speed, claw-shifted Clutch: Wet multi-disc clutch (hydraulically operated) Gear Ratios: 1st: 16/34, 2nd: 18/31, 3rd: 19/28, 4th: 22/27, 5th: 24/25 Features Transmission Oil Type: KTM recommends Motorex Gear Oil SAE 75W/90 or SAE 80W Final Drive: Chain drive, 13/50 (standard sprockets) 📐 Dimensions Exterior Length: Approx. 2145 mm Width: Approx. 810 mm (handlebar width) Height: Approx. 1250 mm (seat height) Seat Height: Approx. 955 mm Wheelbase: Approx. 1480 mm Weights Dry Weight: Approx. 102 kg Wet Weight: Approx. 112 kg (with fluids, estimate) Maximum Load: Not specified for competition use, but typically around 100-120 kg rider and gear. Suspension Travel Front Travel: 300 mm (WP 48mm USD forks) Rear Travel: 335 mm (WP PDS shock absorber) Ground Clearance Ground Clearance: Approx. 357 mm 🛡️ Safety Features Ratings Crash Safety: N/A (Competition off-road vehicles are not subject to standard automotive safety ratings)...