Model:
125 Duke / RC 125 (Engine Shared with 200 Duke / RC 200)
Model Variant:
Engine Service Repair Manual
Platform:
Shared engine platform for 125cc and 200cc models
Engine Code Common:
LC4 (Designation may vary internally, but broadly refers to KTM's single-cylinder liquid-cooled engines of this era)
Market Segment:
Lightweight, performance-oriented entry-level sport motorcycles.
Target Audience:
New riders, commuting, urban riding, track day enthusiasts seeking accessible performance.
Key Competitors:
Yamaha R125/MT-125, Honda CBR125R/CB125F, Kawasaki Ninja 125/Z125.
Engine Design:
Liquid-cooled, single-cylinder, DOHC, 4-valve engine known for its free-revving nature and sporty character.
Chassis Design:
Trellis frame, high-quality suspension components (WP), aggressive styling derived from larger KTM sportbikes.
Brand Philosophy:
Ready To Race DNA, focusing on rider engagement and performance.
Covered Models:
KTM 125 Duke, KTM RC 125, KTM 200 Duke, KTM RC 200
Covered Years:
1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006
Estimated Page Count:
300-400 (Typical for comprehensive engine service manuals of this era)
Manual Type:
Service and Repair Manual
Engine Mechanical:
Cylinder head, valves, camshaft, pistons, connecting rods, crankshaft, lubrication system, cooling system, engine case, gaskets, seals.
Fuel System:
Carburetor (likely Keihin PD or similar), fuel tank, fuel lines, fuel filter, idle control.
Ignition System:
CDI unit, ignition coil, spark plug, stator, rotor, wiring diagrams.
Exhaust System:
Exhaust manifold, muffler, gaskets, mounting hardware.
Electrical System:
Wiring diagrams specific to engine components, charging system (stator, rectifier/regulator), starter motor, battery connections.
Routine Maintenance:
Oil changes, filter replacement, spark plug replacement, valve clearance adjustment, air filter cleaning/replacement, chain adjustment.
Troubleshooting:
Diagnostic procedures for common engine issues (no start, misfires, poor performance), diagnostic codes (if applicable).
Disassembly Assembly:
Step-by-step instructions for engine teardown, component inspection, and reassembly.
Rebuilding:
Detailed procedures for engine rebuilds, including piston ring replacement, bearing replacement, seal replacement, and cylinder honing.
Special Tools:
Identification and usage of specialized tools required for specific repair procedures.
Diagnostic Procedures:
In-depth diagnostic flowcharts and tests for electrical and mechanical systems.
Component Specifications:
Precise measurements for clearances, tolerances, torque specifications, and wear limits for all engine components.
Wiring Diagrams:
Comprehensive and detailed electrical wiring diagrams for engine management and related systems.
Torque Values:
Specific torque values for all fasteners and critical assembly points.
Overhaul Procedures:
Complete overhaul instructions for major engine sub-assemblies.
Engine Type:
Single-cylinder, four-stroke, liquid-cooled, DOHC, 4 valves
Displacement 125:
124.7 cc
Displacement 200:
199.5 cc
Bore Stroke 125:
54 mm x 54.5 mm
Bore Stroke 200:
65.5 mm x 58.5 mm
Compression Ratio:
Approx. 12.3:1 (Varies slightly between 125 and 200)
Horsepower 125:
Approx. 15 hp (limited by A1 license regulations)
Horsepower 200:
Approx. 25 hp
Torque 125:
Approx. 12 Nm
Torque 200:
Approx. 19 Nm
Fuel Delivery:
Carburetor (e.g., Keihin PJ or PD series)
Fuel Type:
Unleaded gasoline, minimum 91 octane (RON+MON)/95 RON
Lubrication System:
Wet sump with oil pump
Cooling System:
Liquid-cooled (radiator and fan)
Instrument Cluster:
Digital LCD instrument cluster displaying speed, RPM, gear indicator, fuel level, trip meters, clock.
ABS:
ABS was typically an optional or standard feature on later models within this range, but not universally across all 1999-2006 variants.
Connectivity Features:
N/A (No Bluetooth or smartphone connectivity in this era).
Oil Change Interval:
Every 5,000 km or 6 months (refer to manual for exact interval)
Valve Clearance Check:
Every 10,000 km
Air Filter Cleaning:
Every 5,000 km or as needed in dusty conditions
Spark Plug Replacement:
Every 10,000 km
Engine Oil Type:
SAE 10W-50, API SL or higher, JASO MA or MA2
Engine Oil Capacity:
Approx. 1.1 liters (with filter change)
Coolant Type:
Mixture of distilled water and ethylene glycol-based antifreeze (50:50 ratio)
Common Wear Items:
Clutch plates, chain and sprockets, wheel bearings, fork seals (typical for performance-oriented bikes).
Electrical Gremlins:
Occasional issues with starter relays or stator connections can occur, particularly with age and mileage.
Carburetor Tuning:
May require periodic adjustment or cleaning, especially if fuel quality varies.
Brand Origin:
KTM AG is an Austrian manufacturer, renowned for its off-road motorcycles and growing presence in street-legal performance bikes.
Segment Introduction:
The 125 and 200 Duke models marked KTM's expansion into the smaller displacement, accessible performance segment, leveraging their expertise from larger models.
Styling Influence:
The 'Duke' naked streetfighter styling and 'RC' full-fairing sports bike styling were adopted, mirroring KTM's larger capacity offerings.
Manufacturing Location:
Primarily manufactured in India by Bajaj Auto Ltd. under license and partnership with KTM.
