🏷️ Basic Information

Make:

KTM

Model:

250/450/525 SX, MXC, EXC

Year:

2004

Product Type:

Engine Parts Book

Chassis Codes:

SX: 2004; EXC: 2004; MXC: 2004

Engine Codes 250:

Likely LC4 derivative or similar single-cylinder off-road engine

Engine Codes 450:

Likely LC4 derivative or similar single-cylinder off-road engine

Engine Codes 525:

Likely LC4 derivative or similar single-cylinder off-road engine

👋 Introduction

Market Segment:

High-performance off-road motorcycles (Motocross and Enduro)

Competitors:

Yamaha YZ series, Honda CRF series, Suzuki RM/DRZ series, Kawasaki KX series, Husaberg, Husqvarna.

Vehicle Attributes:

Powerful single-cylinder engines, robust chassis, capable suspension, designed for competitive off-road riding and racing.

Utility:

Essential for owners and technicians performing engine maintenance, repairs, or parts replacement to ensure accuracy and efficiency.

Target Audience:

KTM Owners, Independent Repair Shops, Enthusiasts

📋 Manual Details

Coverage Scope:

Engine component identification and exploded views

Vehicle Variants Covered:

KTM 250 SX, 450 SX, 525 SX, 250 MXC, 450 MXC, 525 MXC, 250 EXC, 450 EXC, 525 EXC

Estimated Page Count:

Typically 100-200 pages for this type of document, but specific count not provided.

Type:

Parts Catalog / Parts List / Illustrated Parts Manual

Language:

English (standard for KTM manuals of this era)

Format:

Printed (implied by sales context, but could be PDF)

📖 Manual Coverage

Engine Assembly:

Cylinder, Piston, Crankshaft, Connecting Rod, Valves, Camshaft, Carburetor (if applicable), Ignition components (related to engine), Oil pump, Clutch assembly, Gearbox components.

Engine Ancillaries:

Exhaust system components (header, muffler), cooling system components (radiator, hoses if applicable), air filter housing and related.

Disassembly Identification:

Identification of individual parts for disassembly and reassembly.

Assembly Identification:

Identification of individual parts for assembly and reassembly.

Parts Lookup:

Crucial for identifying correct replacement parts.

Depth:

Detailed identification of OEM part numbers, quantities, and relationships between components.

📊 Manual Specifications

File Format:

N/A (assuming printed copy)

Print Quality:

Expect professional-quality printing with clear illustrations and text. (Standard for OEM manuals).

Binding:

Likely perfect bound or saddle-stitched for a printed manual.

Paper Quality:

Durable paper stock suitable for workshop environments, often glossy or semi-gloss for illustrations.

⚙️ Engine Specifications

Engine Type 250:

Single-cylinder, 4-stroke (likely OHC or DOHC, liquid-cooled)

Engine Type 450:

Single-cylinder, 4-stroke (likely OHC or DOHC, liquid-cooled)

Engine Type 525:

Single-cylinder, 4-stroke (likely OHC or DOHC, liquid-cooled)

Bore X Stroke 250:

Specific data not provided, but typically around 76mm x 54.8mm for similar displacements.

Bore X Stroke 450:

Specific data not provided, but typically around 95mm x 63.4mm for similar displacements.

Bore X Stroke 525:

Specific data not provided, but typically around 97mm x 70.5mm for similar displacements.

Horsepower 250:

Estimated 40-45 HP (stock)

Horsepower 450:

Estimated 50-55 HP (stock)

Horsepower 525:

Estimated 55-60 HP (stock)

Torque Peak 250:

Estimated 25-28 lb-ft

Torque Peak 450:

Estimated 33-36 lb-ft

Torque Peak 525:

Estimated 36-40 lb-ft

Fuel Delivery 250:

Carburetor (likely Keihin FCR MX series)

Fuel Delivery 450:

Carburetor (likely Keihin FCR MX series)

Fuel Delivery 525:

Carburetor (likely Keihin FCR MX series)

Fuel Type:

Unleaded gasoline (91 octane or higher recommended)

🔧 Transmission

Transmission Type:

6-speed manual gearbox

Transmission Options:

N/A (standard for this model)

Clutch Type:

Wet multi-plate clutch (hydraulic actuation)

Gear Ratios:

Specific ratios not provided, but designed for aggressive off-road use.

Transmission Fluid Type:

KTM recommends specific motorcycle gear oil or high-quality JASO MA certified transmission fluid.

📐 Dimensions

Wheelbase:

Varies by model (SX, EXC, MXC) but typically around 57-59 inches.

Seat Height:

Varies by model (SX, EXC, MXC) but typically around 37-39 inches.

Dry Weight 250:

Approx. 230-240 lbs (104-109 kg)

Dry Weight 450:

Approx. 240-250 lbs (109-113 kg)

Dry Weight 525:

Approx. 245-255 lbs (111-116 kg)

Fuel Tank Capacity:

Typically 2.5-3.5 gallons (9.5-13 liters)

🛡️ Safety Features

Safety Certification:

Not applicable in the traditional automotive sense for off-road motorcycles; designed for off-road use only.

Braking System:

Hydraulic disc brakes (front and rear) with Brembo calipers.

Suspension System:

High-performance, adjustable upside-down front forks (WP Suspension) and monoshock rear suspension (WP PDS or similar).

Frame Construction:

Chromium-molybdenum steel trellis frame for rigidity and strength.

💡 Technology Features

Infotainment System:

N/A (purpose-built off-road competition machines)

Driver Assistance Features:

N/A (mechanical simplicity prioritized for off-road performance)

Connectivity Features:

N/A

Ignition Type:

Digital CDI ignition with variable ignition timing.

🔧 Maintenance

Oil Change Interval:

Refer to the specific owner's manual, but typically every 15-25 hours of riding for aggressive use.

Air Filter Cleaning:

Frequent cleaning/replacement recommended, often after every few rides depending on conditions.

Valve Adjustment Interval:

Typically every 50-100 hours of riding, depending on use.

Engine Oil Type:

KTM recommends specific semi-synthetic or full-synthetic motorcycle oils (e.g., Motorex Power Synt 4T) with JASO MA/MA2 certification.

Engine Oil Capacity:

Refer to the specific model/year owner's manual; typically around 1.0-1.5 liters (1.0-1.6 US qt).

Coolant Type:

Ethylene glycol-based antifreeze with corrosion inhibitors (typically a 50/50 mix with distilled water).

Common Wear Items:

Clutch plates, piston rings, valve guides, wheel bearings, swingarm bearings, fork seals.

Potential Failures 2004:

Some early LC4 models had issues with cam chain tensioners, stator failures, or electrical connectors; this parts book can help identify replacements.

Carburetor Tuning:

Carburetors (FCR MX) may require periodic adjustment or cleaning, especially when altitude or temperature changes significantly.

📚 Vehicle History

Brand Origins:

KTM AG, an Austrian manufacturer renowned for its off-road racing motorcycles.

Lineage:

These models are part of KTM's long-standing tradition of producing powerful and competitive motocross (SX) and enduro (EXC, MXC) bikes. The LC4 engine platform has been a staple for KTM in various displacements.

Manufacturing Location:

Austria

🏆 Awards & Recognition

Model Awards:

KTM models of this era consistently received accolades in off-road racing publications and events, often winning championships in their respective classes.

Performance Ratings:

Highly rated for power delivery, suspension performance, and chassis handling in the off-road market.

Emissions Certification:

Designed for closed-course competition and off-road use, emission standards may vary by region.