Target Audience:
KTM LC4 owners, mechanics, parts suppliers, and restoration enthusiasts.
Value Proposition:
Essential resource for identifying and ordering correct replacement parts for the LC4 400/640 engine.
Industry Standard:
Factory parts catalogs are the authoritative source for OEM part identification.
Convenience:
Instant digital access, no waiting for physical media.
Assurance:
Full Money Back Guarantee.
Usability:
Zoom in/out functionality for detailed examination of diagrams.
Engine Coverage:
Complete LC4 400 and 640 engines
Components Covered:
Crankcase, cylinder, piston, valves, camshaft, crankshaft, connecting rod, clutch, gearbox, oil pump, cooling system components, ignition system components, carburetor/fuel injection components.
Estimated Pages:
Variable (typical for factory parts catalogs range from 150-400 pages depending on specific model year and variants covered, detailed specifics not provided in product data)
Manual Type:
Parts Manual / Parts Catalog
Engine Internals:
Detailed exploded views and part numbers for all internal engine components.
Lubrication System:
Oil pump, oil filter, oil lines, crankcase lubrication pathways.
Cooling System:
Water pump, thermostat, radiator components, coolant passages.
Fuel System:
Carburetor (Mikuni VM series typically) or fuel injection components, fuel pump (if applicable), fuel lines.
Ignition System:
Ignition coil, spark plug, CDI unit, wiring harnesses related to ignition.
Clutch Assembly:
Clutch plates, springs, basket, pressure plate, operating mechanism.
Transmission Internals:
Gears, shift forks, shift drum, bearings, seals.
Parts Identification:
Identification of all individual components with corresponding OEM part numbers.
Assembly Disassembly Reference:
Provides visual cues for assembly and disassembly order and component placement through exploded diagrams.
Cross Referencing Capabilities:
Facilitates cross-referencing for interchangeable parts or superseded part numbers.
Depth Of Coverage:
Component-level detail for accurate part ordering and identification.
Diagnostic Focus:
Primarily focused on part identification for replacement, not diagnostic procedures.
Searchability:
Likely searchable text within PDF (dependent on scan quality and OCR)
Visual Quality:
Factory Quality (implies clear diagrams and legible text)
Binding Type:
Not Applicable (Digital Download)
Paper Type:
Not Applicable (Digital Download)
Delivery Method:
Instant Download
Physical Media Requirement:
No CD-ROM required
Engine Family:
KTM LC4 Single Cylinder
Displacement 400:
Approximately 373cc (specific variants may differ slightly)
Displacement 640:
Approximately 625cc (specific variants may differ slightly)
Configuration:
Single-cylinder, four-stroke, liquid-cooled (or air-cooled for some early variants)
Valve Train:
SOHC (Single Overhead Camshaft), 4 valves per cylinder
Horsepower 400 Approx:
30-35 HP (typical for 400 models, varies by year/tune)
Horsepower 640 Approx:
48-55 HP (typical for 640 models, varies by year/tune)
Torque 400 Approx:
30-35 Nm (typical for 400 models)
Torque 640 Approx:
55-60 Nm (typical for 640 models)
Fuel Delivery 400:
Mikuni BST 33 or similar carburetor (pre-EFI models)
Fuel Delivery 640:
Mikuni VM 41 or Keihin FCR carburetors, or electronic fuel injection (EFI) on later models.
Fuel Type:
Unleaded gasoline
Transmission Type:
5-speed or 6-speed constant mesh gearbox
Clutch Type:
Wet multi-plate clutch
Gear Ratios:
Specific ratios are detailed within the manual for each gear.
Final Drive:
Chain drive (typically O-ring or X-ring chain)
Transmission Oil Type:
SAE 10W-40 or 10W-50 motorcycle-specific lubricant meeting JASO MA/MA2 specifications.
Transmission Oil Capacity:
Approx. 0.8 - 1.2 liters (refer to specific model year for exact capacity).
Infotainment System:
Not applicable for this model generation, focus is on mechanical components.
Driver Assistance Features:
Not applicable for this model generation.
Connectivity Features:
Not applicable for this model generation.
Ignition Type:
CDI (Capacitor Discharge Ignition) or EFI (Electronic Fuel Injection) on later models.
Emission Controls:
Early models may have minimal emission controls; later models may incorporate catalytic converters or secondary air injection depending on market regulations.
Oil Change Interval:
Typically every 3,000 - 5,000 km or annually, depending on usage and manufacturer recommendations (refer to specific model year manual for exact intervals).
Spark Plug Replacement:
Recommended at intervals of 5,000 - 10,000 km, depending on plug type and usage.
Valve Clearance Check:
Every 5,000 - 10,000 km, critical for maintaining performance and preventing damage.
Engine Oil Grade:
SAE 10W-40 or 10W-50, API SG/SH/SJ or higher, JASO MA/MA2.
Coolant Type:
Ethylene glycol-based antifreeze coolant, 50/50 mix with distilled water. Refer to specific KTM coolant specification.
Common Wear Items:
Clutch plates, valve guides, piston rings, cam chain tensioner, starter gears (on some models).
Potential Failures:
Water pump seal leaks, carburetor jetting issues (depending on altitude/fuel), occasional head gasket issues if overheated.
Preventative Maintenance:
Regular cleaning of the air filter, proper chain lubrication and adjustment, and diligent adherence to service intervals are crucial for longevity.
Manufacturer Origin:
Austria
Brand Specialty:
Off-road, adventure, and high-performance motorcycles.
Lc4 Development:
The LC4 engine platform has been a cornerstone of KTM's range, evolving from earlier models into more refined and powerful iterations, including the 400cc and 640cc displacements.
Production Years Lc4:
The LC4 platform spans several decades, with the 400 and 640 variants being prominent in the late 1990s and early to mid-2000s.
