This document pertains to the 250/450/525 SX, MXC, and EXC models from the 2004 production year. These high-performance off-road motorcycles are celebrated for their powerful single-cylinder engines, robust chassis, and capable suspension systems, making them ideal for competitive motocross and enduro riding. An Austrian manufacturer with a strong heritage in off-road racing, engineered these bikes to deliver exceptional power delivery and handling, often achieving championship status in their classes. The models are characterized by their reliable LC4 engine derivatives, 6-speed manual transmissions with hydraulic clutches, and advanced WP suspension components.
This parts catalog serves as an indispensable resource for owners, technicians, and enthusiasts. It provides detailed identification of all engine components, featuring exploded views crucial for accurate disassembly, reassembly, and parts lookup. The manual covers a wide array of engine parts, including cylinder, piston, crankshaft, valves, camshaft, carburetor, clutch, and gearbox components, as well as related ancillaries like the exhaust and cooling systems. Its comprehensive coverage ensures that users can efficiently identify correct OEM part numbers for maintenance and repair, thereby preserving the performance and longevity of their 250, 450, or 525 SX, MXC, or EXC motorcycles.
Model:
250/450/525 SX, MXC, EXC
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
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
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)
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.
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 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 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.
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 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.
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.
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.
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
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.
