🏷️ Basic Information

Make:

KTM

Model:

250 SX, 300 SX, 250 EXC, 300 EXC, 250 EXC Six Days, 300 EXC Six Days, 250 EXC-F, 300 EXC-F Six Days

Product Code Identifier:

KTM250300SXMXCEXCSERVICEREPAIRMANUAL

👋 Introduction

Segment:

High-performance Off-Road Motorcycles (Enduro and Motocross)

Target Audience:

Enthusiasts, amateur racers, professional mechanics, and KTM owners seeking to perform their own maintenance and repairs.

Competitors:

Yamaha YZ250/WR250, Honda CRF250R/CRF250X, Kawasaki KX250/KLX250, Beta RR250/300, Sherco SE250/300.

Kth Performance Advantage:

Focus on lightweight design, powerful engines (especially the 300cc 2-stroke), and advanced WP suspension.

Manual Value Proposition:

Empowers owners to maintain and optimize their high-performance KTM, saving time and money while ensuring peak condition.

📋 Manual Details

Included Models:

KTM 250 SX, 300 SX, 250 EXC, 300 EXC, 250 EXC Six Days, 300 EXC Six Days (2-stroke); KTM 250 EXC-F, 300 EXC-F Six Days (4-stroke)

Estimated Pages:

300-500 (varies by specific model year and engine variant)

Type:

Service and Repair Manual

Language:

English

Format:

Digital (PDF)

📖 Manual Coverage

Engine:

Complete engine disassembly, assembly, inspection, and repair for both 2-stroke and 4-stroke variants.

Transmission:

Gearbox, clutch, shift mechanism inspection, service, and repair.

Fuel System:

Carburetor (2-stroke) or fuel injection system (4-stroke) diagnosis, cleaning, and adjustment; fuel pump, lines, and filter service.

Ignition System:

CDI/ECU, spark plugs, coils, wiring diagnostics.

Exhaust System:

Muffler and pipe inspection and replacement.

Cooling System:

Radiator, coolant, hoses, water pump inspection and service.

Frame And Suspension:

Frame inspection, fork (WP AER/USD), rear shock absorber (WP XPLOR/Trax) disassembly, assembly, service, and tuning.

Brakes:

Hydraulic brake system (front and rear disc brakes), master cylinders, calipers, brake pads, fluid flush and replacement.

Wheels And Tires:

Wheel bearing inspection, spoke tensioning, tire replacement, wheel balancing.

Electrical System:

Wiring diagrams, battery, lighting, starter system, sensors, and ECU diagnostics.

Bodywork And Plastics:

Fairing, seat, fuel tank, fenders, graphics removal and installation.

Routine Maintenance:

Oil changes, filter replacements, chain adjustment, spark plug checks, general inspection.

Troubleshooting:

Diagnostic charts for common problems, identifying symptoms and potential causes.

Engine Rebuild:

Piston, rings, cylinder, crankshaft, bearings, seals replacement and inspection for 2-stroke and 4-stroke engines.

Suspension Service:

Fork seal replacement, oil changes, shock absorber servicing and revalving guidance.

Brake Bleeding:

Complete guide to bleeding hydraulic brake systems.

Electrical Diagnostics:

Testing circuits, components, and identifying electrical faults using wiring diagrams.

Carburetor Tuning:

Jetting recommendations and adjustment procedures for optimal performance.

Fuel Injection Adjustment:

Basic troubleshooting and potential parameter checks (where applicable).

Torque Specifications:

Detailed torque values for all critical fasteners and components.

Depth:

Comprehensive, from basic maintenance to full engine and component rebuilds.

Diagnostic Capability:

Advanced diagnostic procedures for identifying complex issues.

Specifications Coverage:

Includes detailed technical data, measurements, tolerances, and performance specifications.

📊 Manual Specifications

Quality:

High-resolution, searchable PDF with clear text and diagrams.

Accessibility:

Viewable on desktops, laptops, tablets, and smartphones.

Printability:

Printable pages for at-a-glance reference in a workshop environment.

Digital Format Advantage:

Instant download and easy searchability, no physical binding concerns.

Digital Advantage:

Environmentally friendly, no physical paper required.

⚙️ Engine Specifications

2 Stroke Displacement:

249cc (250 models), 293cc (300 models)

4 Stroke Displacement:

249.9cc (250 EXC-F), 293.5cc (300 EXC-F Six Days)

Configuration:

Single-cylinder, 2-stroke (reed valve induction, transfer port induction, exhaust control) / Single-cylinder, 4-stroke, DOHC, 4-valve

Bore X Stroke 2 Stroke:

72 x 64 mm (250), 72 x 72 mm (300)

Bore X Stroke 4 Stroke:

76 x 54.8 mm (250 EXC-F), 81 x 59.5 mm (300 EXC-F)

Horsepower 2 Stroke Approx:

50-60 HP (varies by model year and tuning)

Horsepower 4 Stroke Approx:

40-50 HP (varies by model year)

Torque 2 Stroke Approx:

45-55 Nm (varies by model year and tuning)

Torque 4 Stroke Approx:

40-45 Nm (varies by model year)

2 Stroke Carburetor:

Keihin PWK 38/39 (2-stroke models), Dell'Orto VHS (older models)

4 Stroke Injection:

Keihin Engine Management System (EMS) with 42mm throttle body (4-stroke models)

Type:

Liquid-cooled, forced circulation via water pump

🔧 Transmission

Type:

6-speed constant mesh

Clutch:

Wet multi-disc clutch (hydraulically operated DDS clutch on many models)

Gear Ratios:

Specific ratios vary by model year and variant, detailed in the manual.

📐 Dimensions

Wheelbase Approx:

1470-1520 mm (varies by model year and variant)

Seat Height Approx:

950-970 mm (varies by model year and variant)

Dry Weight Approx:

100-110 kg (varies by model year and variant)

🛡️ Safety Features

Off Road Focus:

Designed for off-road competition and recreational use; no road-legal safety features or ratings apply in the traditional sense.

Braking Performance:

High-performance Brembo hydraulic disc brakes front and rear for superior stopping power.

Suspension Control:

Advanced WP suspension allows for precise rider control over varied terrain.

Chassis Design:

Strong, lightweight chromoly steel frame for stability and rider feedback.

💡 Technology Features

Features:

Typically minimal to none on competition-focused models. Some EXC models may have basic hour meters or basic digital displays.

Features:

None (designed for rider input and control).

Features:

None.

🔧 Maintenance

Oil Change Engine:

Every 10-15 hours of riding (varies by conditions and model; 2-stroke premix/oil injection)

Air Filter Cleaning:

Every 5-10 hours of riding, or as needed based on dust levels.

Spark Plug Check:

Every 20-30 hours of riding (2-stroke); Every 40-60 hours (4-stroke)

Piston Ring Replacement:

40-60 hours (2-stroke), 80-100 hours (4-stroke piston), 120-160 hours (4-stroke rings)

Suspension Service:

Annual or every 50-100 hours for fork and shock internal service.

Engine Oil 4 Stroke:

Motorex Power Synt 4T 10W/50 or equivalent API SG/SH/SJ/SL/SM/SN, JASO MA/MA2, ACEA A3/B3/B4.

Coolant:

KTM recommends Motorex Coolant M3.0 or equivalent ethylene glycol-based antifreeze with corrosion inhibitors.

Brake Fluid:

DOT 4 hydraulic brake fluid.

2 Stroke Oil:

High-quality synthetic 2-stroke oil specifically formulated for off-road competition (e.g., Motorex Cross Power 2T).

2 Stroke Specific:

Carburetor jetting sensitivity to altitude/temperature, potential for clutch wear with aggressive use, power valve cleaning/adjustment (older models).

4 Stroke Specific:

Regular checks of fuel pump filter (TPI models), valve clearance adjustments, potential for linkage bearing wear.

General:

Chain and sprocket wear, spoke tension maintenance, wheel bearing inspection, suspension seal maintenance.

📚 Vehicle History

Ktm Specialization:

KTM AG is an Austrian manufacturer renowned for its off-road racing motorcycles, with a significant presence in Motocross, Enduro, and Rally racing.

Sx Lineage:

The SX line represents KTM's pure motocross competition models, known for aggressive performance and cutting-edge technology.

Exc Lineage:

The EXC line is KTM's enduro offering, built for off-road endurance and trail riding, often featuring homologation for street legality in some markets and specific components like larger fuel tanks and lighting.

Engine Development:

Continuous development in both 2-stroke (TPI - Transfer Port Injection on newer models) and 4-stroke technologies, with a focus on power delivery and reliability.

Manufacturing Location:

Austria (primary), potentially some components or assembly in other global locations.

🏆 Awards & Recognition

Racing Success:

KTM's SX and EXC models are consistently winners in professional motocross and enduro racing series worldwide, indicating superior engineering and performance.

Editorial Reviews:

Frequently praised by automotive journalists and industry publications for their class-leading power, handling, and suspension.