Segment:
High-performance Motocross / Off-Road Competition
Purpose:
Designed for serious motocross riders and competitors, offering peak performance and handling
Competitors:
Yamaha YZ450F, Honda CRF450R, Kawasaki KX450F, Suzuki RM-Z450
Engine Design:
Lightweight, single-cylinder, SOHC, fuel-injected engine with a focus on power delivery and responsiveness
Chassis Design:
Advanced steel-chrome-molybdenum frame offering excellent rigidity and rider feedback, high-quality WP suspension components
Handling:
Renowned KTM handling characteristics, prioritizing agility and precision
Primary Coverage:
Full service, repair, and workshop procedures for the 2011 KTM 450 SX-F
Secondary Coverage:
Troubleshooting, diagnostics, maintenance schedules, electrical system diagrams, torque specifications, component removal/installation
Estimated Pages:
300-400 (Typical for this model year and manual type)
Type:
Factory Service Manual / Workshop Manual
Format:
PDF (Downloadable)
Engine:
Engine assembly, disassembly, valve adjustment, piston/cylinder inspection, crankshaft, connecting rod, lubrication system, cooling system (liquid-cooled), fuel injection system (EFI), ignition system
Transmission:
Gearbox disassembly and reassembly, clutch operation and service, shift mechanism, lubrication
Chassis:
Frame inspection, swingarm, linkage system, bearings, steering head bearings, suspension (forks and rear shock absorber) overhaul and adjustment, wheel and tire service
Electrical:
Wiring diagrams, battery maintenance, charging system (stator, regulator/rectifier), starter motor, lighting system, sensor identification and testing, ECU diagnostics
Brakes:
Hydraulic brake system service (front and rear calipers, master cylinders, brake lines), brake pad replacement, bleeding procedures, rotor inspection
Fuel System:
Fuel pump, fuel filter, injectors, throttle body service
Exhaust System:
Muffler and header pipe service
Maintenance:
Oil change intervals, filter replacement, spark plug replacement, air filter cleaning/replacement, chain adjustment and lubrication, coolant checks and changes, brake fluid replacement
Troubleshooting:
Diagnostic flowcharts for common performance issues, starting problems, electrical faults
Repair:
Step-by-step instructions for component removal, repair, and reinstallation
Diagnostics:
Identification of error codes, sensor testing procedures
Depth:
Comprehensive; covers basic scheduled maintenance through complete engine and chassis overhauls
Engine Type:
Four-stroke, single-cylinder, liquid-cooled, DOHC
Displacement:
449.3 cc (27.4 cubic inches)
Bore X Stroke:
97.0 mm x 60.8 mm (3.82 in x 2.39 in)
Compression Ratio:
12.3:1
Horsepower Estimated:
~50-55 HP (at crankshaft, varies with tuning)
Torque Estimated:
~45-50 Nm (at crankshaft, varies with tuning)
Fuel Delivery:
Electronic Fuel Injection (EFI) with Keihin throttle body (42mm)
Fuel Type:
Unleaded gasoline, minimum 95 RON (Research Octane Number)
Oil Capacity:
Approx. 1.1 Liters (1.16 US qt)
Oil Type:
Semi-synthetic or fully synthetic SAE 10W/40 motorcycle oil (specific KTM recommendation in manual)
Ignition System:
Digital CDI with variable ignition timing
Cooling Type:
Liquid cooling
Coolant Capacity:
Approx. 0.7 Liters (0.74 US qt)
Coolant Type:
Ethylene glycol based coolant with corrosion inhibitors (e.g., Motorex Coolant M3.0)
Type:
Constant mesh, 4-speed
Clutch:
Wet multi-disc clutch (hydraulically operated)
Final Drive:
Chain drive (520 pitch, 15T front / 48T rear standard gearing)
Gear Ratios:
Detailed in manual (typically 1st: ~2.5, 2nd: ~1.8, 3rd: ~1.4, 4th: ~1.0)
Transmission Oil:
Same oil as engine lubrication (check manual for specific type and capacity for gearbox)
Wheelbase:
Approx. 1475 mm (58.07 inches)
Seat Height:
Approx. 955 mm (37.6 inches)
Ground Clearance:
Approx. 330 mm (12.99 inches)
Dry Weight:
Approx. 106 kg (233.7 lbs) (without fuel)
Fuel Tank Capacity:
Approx. 7.5 Liters (1.98 US gal)
Front Wheel:
21 x 1.60 inches
Rear Wheel:
19 x 1.85 inches
Front Tire:
80/100-21 (e.g., Dunlop Geomax MX51)
Rear Tire:
110/90-19 (e.g., Dunlop Geomax MX51)
Safety Certification:
Not applicable for off-road competition motorcycles (designed for closed course use)
Brakes:
Hydraulic disc brakes (front and rear) with wave-style rotors for improved heat dissipation and performance
Frame:
High-strength steel-chrome-molybdenum frame designed for impact absorption and rigidity
Handlebars:
Fat-bar handlebars (e.g., Renthal) with knuckle guards for rider protection
Infotainment System:
N/A (Competition motocross bike, no infotainment features)
Assistance Features:
N/A (Competition motocross bike, no electronic rider aids like traction control or ABS)
Connectivity Options:
N/A (Competition motocross bike)
ECU Capabilities:
Basic engine control unit (ECU) managing fuel injection and ignition timing. More advanced tuning might require aftermarket ECU mapping.
Engine Oil Change:
Every 5-10 hours of riding, or annually, whichever comes first (refer to manual for exact recommendation based on usage).
Air Filter Cleaning:
Every 2-4 hours of riding in dusty conditions, or before each race.
Valve Clearance Check:
Every 15-25 hours of riding, or as recommended in the manual.
Spark Plug Replacement:
Inspect at regular intervals; replace as needed based on condition (typical lifespan 20-40 hours).
Engine Oil Specification:
KTM recommends specific Motorex motorcycle oils; SAE 10W/40 is common. Consult manual for exact grade and specification (e.g., Motorex Power Synt M3.0).
Brake Fluid Specification:
DOT 4 hydraulic brake fluid.
Coolant Specification:
Ethylene glycol-based coolant with anti-corrosion additives (e.g., Motorex Coolant M3.0).
Common Wear Items:
Clutch plates, brake pads, chain and sprockets, wheel bearings, steering head bearings, suspension seals.
Engine Considerations:
Regular valve adjustment is crucial for maintaining performance and longevity. Ensure proper cooling system maintenance to prevent overheating.
Chassis Considerations:
Regularly inspect and grease linkage bearings and steering head bearings. Check spokes for tension.
Heritage:
KTM (Kraftfahrzeuge Trunkenpolz Mattighofen) has a rich history in off-road racing, particularly motocross and enduro, known for its 'Ready to Race' philosophy.
Sx Series Evolution:
The 450 SX-F represents the evolution of KTM's open-class motocross bikes, continuously refined for performance, handling, and rider ergonomics. The 2011 model saw significant updates from previous generations.
Manufacturing Location:
Mattighofen, Austria (Primary)
