Model:
250SX, 250 EXC, 250 XCF, 250 SXS
Model Variants:
Motocross (SX), Enduro (EXC), Cross Country (XCF), Special/Factory Edition (SXS)
Model Years:
2005, 2006, 2007, 2008
Engine Code Prefix:
Typically starts with "250" followed by specific codes for engine families (e.g., EXC, SX)
Target Audience:
KTM owners, independent motorcycle mechanics, performance tuners.
Value Proposition:
Empowers users to perform detailed engine maintenance and repairs, saving on dealership costs and enhancing vehicle longevity.
Differentiation:
Focuses specifically on the KTM 2-stroke engine platform of the era, providing model-specific nuances often missing in generic guides.
Modularity:
Covers multiple closely related models (SX, EXC, XCF, SXS) sharing the same core engine architecture, offering broad applicability within the product line.
Accuracy:
Derived from official KTM factory documentation, ensuring precision in specifications and procedures.
Manual Scope:
Comprehensive Engine Workshop Repair Manual
Page Count:
Information not explicitly provided in product description, but typical workshop manuals of this era are 300-500+ pages.
Manual Type:
Workshop Repair Manual
Language:
English (presumed for a global market, common for KTM manuals of this period)
Format:
Likely a digital format (PDF) for distribution, potentially also available in printed form.
Engine Mechanical:
Complete engine assembly, disassembly, inspection, repair, and overhaul.
Cooling System:
Radiator, hoses, water pump, thermostat (if applicable).
Fuel System:
Carburetor (Mikuni TM28/38 type common for this era), fuel lines, fuel petcock, fuel tank.
Ignition System:
Ignition coil, CDI unit, spark plug, stator, flywheel.
Lubrication System:
Premix lubrication or separate oil injection system components (if applicable), gearbox lubrication.
Exhaust System:
Exhaust pipe, silencer, gaskets.
Transmission Internal:
Gearbox assembly, disassembly, inspection, repair of gears, shift forks, drum.
Clutch System:
Clutch assembly (often hydraulic actuation), plates, springs, pressure plate, actuator.
Starting System:
Kick starter mechanism.
Routine Maintenance:
Spark plug inspection/replacement, air filter cleaning/replacement, chain maintenance, pre-mix ratio, coolant checks.
Engine Rebuild:
Complete engine disassembly, cleaning, inspection for wear, component replacement (piston, rings, cylinder, crankshaft, bearings, seals).
Carburetor Tuning:
Jetting, float level adjustment, idle speed, mixture screw settings.
Troubleshooting:
Diagnostic procedures for common starting, running, and performance issues.
Torque Specifications:
Detailed torque values for all critical fasteners.
Special Tool Requirements:
Identification and usage of specialized tools for specific repair tasks.
Electrical Diagnostics Engine:
Wiring diagrams for engine-related components (ignition, stator).
Depth Of Coverage:
Advanced diagnostics, complete engine rebuilds, component-level repair.
Diagnostic Charts:
Likely includes symptom-to-cause troubleshooting charts.
Component Tolerances:
Detailed specifications for wear limits and clearances for engine components.
File Format:
PDF (common for digital manuals)
Searchable Text:
Likely a searchable PDF for efficient information retrieval.
Print Quality:
High-resolution for clear diagrams and text (if digital). Print quality would depend on the printing service.
Binding Type:
Spiral-bound or comb-bound (common for workshop manuals for lay-flat use).
Paper Type:
Durable, possibly coated paper to resist workshop grease and dirt.
Engine Configuration:
Single-cylinder, 2-stroke
Displacement:
249 cc (approx.)
Bore X Stroke:
Typically around 66.4 mm x 72 mm (subject to specific model year variations).
Cooling Type:
Liquid-cooled
Reed Valve System:
Yes, usually with a specific KTM or Moto Tassinari V-Force reed block.
Horsepower:
Estimated 40-48 hp (depending on model variant and tuning).
Torque:
Estimated 30-35 Nm (depending on model variant and tuning).
Carburetor Model:
Mikuni TM (e.g., TM28, TM38) or Keihin PWK.
Fuel Type:
Unleaded gasoline mixed with 2-stroke oil (pre-mix).
Premix Ratio:
Typically 1:40 or 1:50 (refer to manual for precise recommendation).
Engine Oil Type:
Specific 2-stroke synthetic or semi-synthetic oil meeting KTM specifications (e.g., Motorex).
Gearbox Oil Type:
SAE 10W/50, API SG or higher, meeting JASO MA standards (e.g., Motorex Gear Oil).
Safety Certification:
Off-road competition focused, not subject to typical road vehicle safety ratings.
Braking System:
Hydraulic disc brakes (front and rear), Brembo calipers common.
Suspension System:
High-performance WP Suspension (USD forks, monoshock rear), adjustable for compression and rebound.
Frame Construction:
Chromoly steel perimeter frame.
Piston Replacement:
Recommended every 40-100 hours of heavy use, depending on riding style and maintenance.
Top End Rebuild:
Frequent inspection advised, especially after aggressive riding. Full rebuild typically every 100-200 hours.
Gearbox Oil Change:
Every 15-20 hours or annually.
Clutch Fluid Flush:
Annually.
Coolant Type:
Ethylene glycol based coolant with anti-corrosion additives, mixed 50/50 with distilled water.
Power Valve Sticking:
Carbon buildup can cause the power valve mechanism to stick, leading to poor performance. Requires regular cleaning.
Clutch Lever Drag:
Can occur due to heat or fluid contamination, affecting clutch engagement. Bleeding and fluid change are common solutions.
Carburetor Jetting Sensitivity:
2-stroke engines are sensitive to altitude and temperature changes, requiring proper jetting adjustments.
Crankshaft Bearing Wear:
High-stress environment can lead to premature wear of crankshaft main bearings, necessitating replacement during engine rebuilds.
Ktm Offroad Legacy:
KTM has a long and successful history in motocross and enduro racing, known for 'Ready to Race' performance.
Engine Development:
The 250cc 2-stroke platform was a staple for KTM in this period, with continuous refinements to power delivery, chassis, and suspension.
Sx Vs Exc Difference:
SX models are pure motocross, lighter, stiffer suspension. EXC models are road-legal (in many regions) enduro bikes with broader powerbands, softer suspension, and lighting.
Manufacturing Location:
Austria
