Official KTM 250 EXC, 400 EXC, 450 SX/MXC/EXC, 525 SX/MXC/EXC Racing - Factory Service & Repair Manual 2000-2005

KTM 250-610 Racing Series Service & Repair Manual - 2000-2005

Ensure your KTM Racing machine stays in peak competition condition with this professional-grade factory service manual. Designed for owners and technicians who demand factory-level precision, this documentation provides the critical data needed to reduce downtime and perform high-stakes repairs with absolute confidence.

Model Coverage & Hardware Details:

This manual covers the high-performance 4-stroke Racing series including:

• KTM 250 EXC Racing (2002-2005): 249.6cc, Bore/Stroke 75/56.5 mm.
• KTM 400 EXC/SX/MXC Racing (2000-2005): 398cc, Bore/Stroke 89/64 mm.
• KTM 450 SX/MXC/EXC Racing (2003-2005): 449cc, Titanium valves on SX models.
• KTM 520/525 SX/MXC/EXC Racing (2000-2005): 510cc, Bore/Stroke 95/72 mm.
• Specialist Models: Includes coverage for the 450/540 SXS, 450/525 SMR, and 610 Crate Racing engines.

Professional Benefits:

• Precision Maintenance: Access exact factory tolerances for valve trains and engine internals to prevent premature component failure.
• Systematic Troubleshooting: Resolve complex electrical or fueling issues quickly using dedicated diagnostic charts.
• Enhanced Safety: Follow verified torque specifications and brake system service standards to ensure rider safety under extreme racing conditions.
• Cost Efficiency: Perform advanced engine overhauls and suspension tuning in-house, avoiding expensive dealership labor rates.

What’s Included in This Service Manual Set:

This digital technical library (Art. No. 3.206.023-E) includes the full Repair Manual for the 250–610 Racing series, featuring complete engine dismantling/assembly, chassis service, and specialized technical supplements for various model years. It encompasses detailed periodic maintenance schedules, tightening torque tables, and full-color wiring schematics.

TECHNICAL DATA & STRUCTURE

Technical Identification & Specifications

• Serial Number Locations: - Chassis Number: Stamped on the right side of the steering head tube.
  • Engine Number: Stamped into the left side of the engine casing, directly below the engine sprocket.
• Factory Specifications (Proof of Depth):
  • Valve Clearance (Cold): Intake: 0.12 mm (0.0047 in) / Exhaust: 0.12 mm (0.0047 in).
  • Oil Pressure Bypass Valve: Pressure spring minimum length: 23.5 mm.
  • Piston Fitting Clearance: 0.030 mm – 0.099 mm (Model dependent; Wear limit: 0.12 mm).
  • Cylinder Run-out/Distortion: Maximum allowable head distortion: 0.10 mm.
  • Main Torque Value: Cylinder head bolts (M10): 40/50 Nm; Primary gear nut (M20x1.5): 150 Nm with Loctite 243.

Visual & Diagnostic Features

• Exploded Parts Views: Comprehensive visual breakdowns for engine cases, cylinder heads, and transmission assemblies.
• Detailed Electrical Wiring Diagrams: Full-page schematics for EXC, SX, and MXC versions, including 4K-3A/B ignition system layouts.
• Component Routing: Detailed instructions for fuel line, throttle cable, and wire harness placement.
• Troubleshooting Flowcharts: Professional diagnostic tables covering engine performance, starting issues, and electrical system faults.

Contents at a Glance

• Engine Overhaul: Complete dismantling, servicing individual components (crankshaft, valves, transmission), and reassembly.
• Fuel System: Deep dive into Keihin FCR and FCR-MX (37/39/41) carburetors, including float height and accelerator pump adjustments.
• Suspension & Chassis: WP 43/48 Fork and PDS Shock Absorber standard adjustments, bleeding procedures, and spring replacement.
• Periodic Maintenance: Specific service intervals based on operating hours and fuel consumption for competition use.

Professional Value

Provides factory-defined wear limits and service standards, such as crankshaft run-out (max 0.12 mm) and brake disc wear limits (min 2.5 mm front / 3.5 mm rear), to ensure maximum component longevity and prevent catastrophic mechanical failure during competition.