Positioning:
High-performance off-road motorcycles aimed at competitive racing (SX/XC) and demanding enduro riding (EXC). KTM established itself as a premium brand in this segment.
Competitors:
Primary competitors include Yamaha YZ/WR series, Honda CRF/XR series, Suzuki RM/DRZ series, and Kawasaki KX/KLX series in their respective displacement classes.
Engine Variants:
Differentiated by engine size (250cc, 400cc, 450cc, 525cc) and intended use (SX-F for Motocross, EXC for Enduro).
Offroad Focus:
Designed for off-road conditions, featuring robust suspension, aggressive tire treads, and lightweight construction.
Coverage:
Comprehensive coverage for 2006 KTM 250 SX-F, 250 EXC Racing, 400 EXC Racing, 450 SX XC EXC Racing, and 525 SX XC EXC Racing models.
Pages:
Estimated 200-300 pages (typical for a multi-model owner's manual of this era)
Language:
English (Assumed primary language based on common market distribution)
Format:
Likely printed booklet; Digital PDF is a common aftermarket format.
Engine Systems:
Engine identification, operation, lubrication, cooling, fuel, exhaust, starting, ignition, and emissions control.
Drivetrain Systems:
Clutch operation, transmission (gearbox) operation, and chain drive maintenance.
Chassis Systems:
Frame, suspension (front forks, rear shock absorber), steering, wheels, tires, brakes (hydraulic disc front and rear), and control levers.
Electrical Systems:
Battery, lighting (if applicable for EXC models), ignition system components, and general electrical troubleshooting.
Maintenance Procedures:
Pre-ride checks, regular inspection points, cleaning, lubrication (chain, cables), air filter cleaning/replacement, oil changes, spark plug inspection/replacement, brake pad inspection, tire pressure checks.
Troubleshooting Procedures:
Basic problem diagnosis for common operational issues, such as starting difficulties, engine performance problems, and brake issues.
Operator Procedures:
Riding instructions, safe operation guidelines, vehicle identification, instrument panel explanation, control operation, storage recommendations.
Depth:
Owner-level maintenance and operation. Focuses on what the rider needs to know for safe and correct use, basic upkeep, and minor adjustments. Does not typically cover in-depth engine teardown or complex electrical diagnostics like a service manual.
Engine Type:
Four-stroke, single-cylinder (OHC or DOHC depending on model variant, typically DOHC for SX-F and EXC Racing) Liquid-cooled.
Bore X Stroke 250:
Approx. 76 mm x 54.8 mm (for 250cc models)
Bore X Stroke 400:
Approx. 84 mm x 72 mm (for 400cc models)
Bore X Stroke 450:
Approx. 95 mm x 63.4 mm (for 450cc models)
Bore X Stroke 525:
Approx. 97 mm x 71.4 mm (for 525cc models)
Compression Ratio:
Typically in the range of 11.5:1 to 12.5:1, varying by specific model.
Horsepower 250:
Estimated 35-40 HP (peak, varies by model and tuning)
Horsepower 450:
Estimated 45-50 HP (peak, varies by model and tuning)
Torque:
Torque figures vary significantly by displacement. Manual would detail specific ranges.
Fuel Delivery:
Carburetor (Keihin FCR series is common for this era)
Carburetor Size:
Typically 36mm, 39mm, or 41mm depending on engine size and model variant.
Fuel Type:
Unleaded gasoline, minimum 95 RON (Research Octane Number).
Transmission Type:
Constant Mesh, 5-speed sequential gearbox
Optional Features:
N/A (Off-road bikes typically have fixed gear ratios)
Clutch Type:
Hydraulic-actuated wet multi-plate clutch
Final Drive:
Chain drive (DID or similar premium brand)
Frame Type:
Chromium-molybdenum steel central double-cradle frame with bolted-on subframe.
Suspension Front:
WP USD (Upside Down) telescopic fork, typically 48mm diameter with adjustable compression and rebound damping.
Suspension Rear:
WP Monoshock (PDS - Progressive Damping System), with adjustable preload, compression, and rebound damping.
Brakes Front:
Hydraulic disc brake with two-piston caliper. Rotor size typically 260mm.
Brakes Rear:
Hydraulic disc brake with single-piston caliper. Rotor size typically 220mm.
Wheelbase:
Varies by model, typically around 1470-1490 mm.
Dry Weight 250:
Approx. 105-110 kg (varies by model)
Dry Weight 450:
Approx. 110-115 kg (varies by model)
Fuel Tank Capacity:
Typically 7-9 liters (1.8-2.4 US gallons)
Safety Certification:
N/A (Motorcycles are typically not rated by organizations like NHTSA or Euro NCAP in the same way cars are. Compliance with local road regulations for EXC models is expected.)
Active Safety:
Effective hydraulic brakes, responsive suspension, and ergonomic rider controls are key active safety features.
Passive Safety:
Robust frame construction, protective bodywork (plastics), and the inherent design of a dirt bike to absorb impacts.
Operational Guidelines:
Manual provides extensive safety warnings regarding protective gear, riding conditions, vehicle limitations, and maintenance.
Infotainment Features:
N/A (Off-road motorcycles do not typically feature infotainment systems.)
Assistance Features:
N/A (No electronic driver assistance systems like ABS or traction control on these models.)
Connectivity Features:
N/A (No electronic connectivity features.)
Instrument Panel:
Basic digital or analog instrumentation for speed, engine hours, odometer, and indicator lights (e.g., neutral, oil pressure).
Oil Change Interval:
Typically every 15-20 operating hours or annually. Manual will specify exact intervals based on usage.
Air Filter Cleaning:
Recommended every 5-10 operating hours or as needed depending on dust conditions.
Spark Plug Inspection:
Recommended every 20-30 operating hours.
Valve Clearance Check:
Typically every 20-40 operating hours. Crucial for performance and engine longevity.
Engine Oil Type:
KTM recommends specific grades of semi-synthetic or fully synthetic motorcycle engine oil meeting API SG, SH, SJ or higher and JASO MA specifications. Common viscosity grades are 10W-40 or 10W-50.
Engine Oil Capacity:
Varies by model and engine size. Typically around 0.8 - 1.2 liters (with filter change).
Coolant Type:
Ethylene glycol-based coolant with corrosion inhibitors. Typically a 50/50 mix with distilled water.
Brake Fluid Type:
DOT 4 hydraulic brake fluid.
Clutch Fluid Type:
DOT 4 hydraulic clutch fluid (if hydraulic).
Common Wear Items:
Clutch plates, brake pads, chain and sprockets, wheel bearings, steering head bearings, and suspension seals are common wear items on performance off-road bikes of this era.
Engine Specific Notes:
Regular valve clearance checks are critical for these high-revving engines. Piston and ring wear can be accelerated with aggressive use.
Cooling System Maintenance:
Ensuring the cooling system is clean and the coolant is fresh is vital to prevent overheating during demanding use.
Ktm Heritage:
KTM, an Austrian manufacturer, has a strong heritage in off-road motorsports, particularly motocross and enduro, dating back to the 1950s. Known for its 'Ready to Race' philosophy.
Sx-F Evolution:
The SX-F line represents KTM's dedicated motocross racing platform. The 250 SX-F was introduced as a competitive four-stroke alternative to two-stroke motocross bikes. Evolution includes chassis updates, engine performance improvements, and suspension advancements year over year.
Exc Evolution:
The EXC line is KTM's dedicated enduro racing platform, often street-legal in some markets (though this manual may cover off-road only versions). The 250, 400, 450, and 525 EXC models were developed to offer a range of power and usability for various enduro disciplines.
Production Location:
Austria (primarily)
Generation Era:
This period represented a significant shift for KTM towards four-stroke dominance in off-road racing, with continuous development in engine technology and chassis design.
Motorsport Achievements:
KTM motorcycles, including models from this era, have a strong track record in professional motocross and enduro championships globally. This manual supports owners participating in such events.
Performance Ratings:
KTMs are generally well-regarded for their performance, handling, and durability in the off-road segment. Reviews from the time would highlight their competitive edge.
