Model:
250 EXC, 400 EXC, 450 EXC, 520 EXC, 525 EXC
Model Variant:
All EXC Models
Model Years Covered:
2000, 2001, 2002, 2003
Chassis Codes:
LC4 Platform (Specific codes vary by exact model and year)
Engine Codes:
LC4 Engine Variants (e.g., 250, 400, 450, 520, 525 displacements)
Market Segment:
High-performance off-road motorcycles (Enduro/Dual-Sport).
Target Audience:
KTM owners, independent repair shops, DIY enthusiasts.
Competitors During Era:
Honda CRF, Yamaha WR, Suzuki DR-Z, Kawasaki KLX, Husqvarna TE series.
Key Manual Selling Point:
Provides owners and technicians with the detailed, accurate information needed to maintain and repair these rugged KTM LC4 models.
Vehicle Reputation:
Known for their powerful engines, robust chassis, and off-road prowess, often favored for enduro racing and demanding terrain.
Engine Overhaul:
Complete disassembly, inspection, repair, and reassembly of engine components.
Fuel System:
Carburetor tuning, cleaning, rebuilding; fuel pump diagnostics (if applicable); fuel tank and lines.
Ignition System:
Ignition coil testing, spark plug specifications, CDI unit diagnostics.
Transmission And Clutch:
Gearbox inspection, repair, clutch adjustment, replacement of friction plates.
Suspension Systems:
Front fork (WP USD) disassembly, seal replacement, oil level and type specifications. Rear shock absorber inspection and service.
Braking System:
Front and rear brake caliper service, master cylinder overhaul, brake pad replacement, fluid bleeding procedures, disc inspection.
Electrical System:
Wiring diagrams, component testing (lights, indicators, starter, battery), troubleshooting electrical faults.
Cooling System:
Radiator inspection, coolant type and capacity, hose replacement, fan operation (if equipped).
Chassis And Frame:
Frame inspection for damage, steering head bearing service, swingarm lubrication and bearing check.
Bodywork And Plastics:
Fairing removal and installation, seat maintenance, fuel tank mounting.
Routine Maintenance:
Oil changes, filter replacements, chain adjustment, air filter cleaning.
Troubleshooting Guides:
Step-by-step diagnostic procedures for common and complex issues.
Component Rebuilds:
Detailed instructions for rebuilding carburetors, brake calipers, water pumps, etc.
Torque Specifications:
Essential torque values for critical fasteners across all systems.
Special Tool Requirements:
Identification of specific tools needed for certain repair procedures.
Depth Of Coverage:
In-depth mechanical and electrical repairs, covering everything from basic servicing to complete engine rebuilds and chassis overhauls.
Diagnostic Capabilities:
Advanced troubleshooting techniques, symptom-to-cause analysis.
Engine Type:
Single-cylinder, four-stroke, liquid-cooled (LC4).
Bore X Stroke 250:
72 mm x 60 mm (approximate)
Bore X Stroke 400:
84 mm x 72 mm (approximate)
Bore X Stroke 450:
95 mm x 63.4 mm (approximate)
Bore X Stroke 525:
97 mm x 70.6 mm (approximate)
Compression Ratio General:
Approx. 11.0:1 - 12.5:1 (varies by displacement)
Valve Actuation:
SOHC (Single Overhead Camshaft), 4 valves
Horsepower 250:
Approx. 30-35 HP
Horsepower 400:
Approx. 40-45 HP
Horsepower 450/525:
Approx. 45-55 HP
Torque General:
Substantial torque output, especially in 450/525 models, optimized for off-road traction.
Carburetion:
Keihin flatside carburetors (e.g., PWK 39, 39.5, 41mm, varies by model/year).
Fuel Type:
Unleaded gasoline, minimum 91 octane (RON+MON)/95 AKI.
Oil Type:
JASO MA certified motorcycle specific 4-stroke engine oil.
Oil Capacity:
Approx. 1.5 - 2.0 liters (varies by model, check manual for exact amount with filter change).
Frame Type:
Chromoly steel perimeter frame.
Front Suspension Type:
WP USD (Upside-Down) telescopic fork.
Rear Suspension Type:
WP PDS (Progressive Damping System) Monoshock.
Front Brake:
Hydraulic disc brake.
Rear Brake:
Hydraulic disc brake.
Dry Weight Approx:
115-125 kg (depending on model and exact configuration).
Fuel Tank Capacity:
Approx. 8-9.5 liters (depending on model/year).
Wheelbase Approx:
1460-1480 mm (depending on model/year).
Seat Height Approx:
950-970 mm (depending on model/year).
Safety Ratings:
N/A (Motorcycle safety is primarily rider-dependent; manual focuses on mechanical safety and correct assembly).
Braking Performance:
High-performance hydraulic disc brakes front and rear, essential for controlled stopping in off-road conditions.
Suspension Stability:
WP suspension provides excellent damping and control, crucial for maintaining stability over rough terrain.
Frame Integrity:
Robust chromoly steel frame designed for durability and rider confidence.
Oil And Filter Change:
Every 3,000-5,000 km or annually (check manual for specific recommendation based on usage).
Air Filter Cleaning:
Every 1,000-2,000 km or more frequently in dusty conditions.
Chain Lubrication Adjustment:
Regularly, or every 500-1000 km, and after washing or riding in wet conditions.
Valve Clearance Check:
Every 6,000-10,000 km (refer to manual for exact interval).
Engine Oil Specification:
SAE 10W-40 or 15W-50, JASO MA/MA2 certified (e.g., Motorex Power Synt 4T).
Coolant Specification:
Ethylene glycol-based coolant with corrosion inhibitors, mixed 50/50 with distilled water (e.g., Motorex Coolant M3.0).
Brake Fluid Specification:
DOT 4 or DOT 5.1 (check manual for specific recommendation).
Fork Oil Specification:
WP recommend specific fork oils, typically SAE 5W or 10W (check manual for exact type and volume).
Known Issue Water Pump Seal:
Occasional failure of the water pump seal, leading to coolant leaks. Manual details replacement procedure.
Known Issue Carburetor Jetting:
Can be sensitive to altitude and temperature changes; proper jetting is crucial for optimal performance. Manual provides tuning guidance.
Known Issue Cam Chain Tensioner:
Some models may benefit from inspecting or replacing the cam chain tensioner for optimal engine noise.
Known Issue Radiator Hoses:
Degradation of coolant hoses over time requires regular inspection and replacement to prevent leaks.
Ktm Heritage:
KTM AG is an Austrian motorcycle manufacturer renowned for its off-road competition success, particularly in motocross, enduro, and Dakar Rally.
Lc4 Platform Significance:
The LC4 platform, introduced in the mid-1980s, has been a cornerstone of KTM's street-legal off-road and dual-sport offerings, known for its potent single-cylinder engines.
Model Year Changes 2000-2003:
This period saw significant refinements in the LC4 line, including updates to suspension (WP forks became standard), engine tuning, chassis geometry, and styling.
Production Location:
Austria (KTM's primary manufacturing base).
Market Impact:
These models were popular for their go-anywhere capability, blending enduro performance with street legality, making them versatile machines for adventure and trail riding.
Brand Recognition:
KTM is widely recognized for building highly capable and durable off-road motorcycles with strong racing pedigrees.
Model Era Reviews:
These LC4 models generally received positive reviews for their power, suspension, and off-road capability, often considered class-leading in their segments.
Manual Authority:
This manual serves as an authoritative guide, reflecting the technical documentation and procedures intended by the manufacturer for service personnel.
