🏷️ Basic Information

Make:

KTM

Model:

SX / MXC Series (Engine Specific)

Engine Codes:

250cc, 300cc, 380cc 2-Stroke Engines (Specific codes vary by year and model variant, detailed in manual)

👋 Introduction

Market Position:

Specialized service documentation for KTM's performance off-road motorcycles, catering to owners and independent workshops seeking in-depth engine repair capabilities.

Competitive Analysis:

Provides a critical resource for maintaining and repairing a specific generation of potent 2-stroke engines that were popular in motocross (SX) and off-road (MXC) racing. Competes with generic workshop manuals or less detailed third-party guides.

Key Features:

Engine-focused detail, model year coverage for 1999-2002, specific to 250/300/380cc displacements, essential for rebuilds and major repairs.

📋 Manual Details

Primary Coverage:

Engine Systems Only

Page Count:

153

Manual Type:

Engine Repair Manual

Language:

English (Assumed, typical for manufacturer manuals of this era)

Format:

Printed Manual (Standard for the era, PDF likely a reproduction)

📖 Manual Coverage

Engine Systems:

Top End Rebuild, Bottom End Rebuild, Carburetor, Ignition System, Cooling System (if applicable), Clutch Assembly, Crankcase, Cylinder, Piston, Connecting Rod, Crankshaft, Gearbox (internal components), Power Valve System, Exhaust System Interface (engine mount points), Sealing and Gaskets, Lubrication System

Repair Procedures:

Disassembly, Inspection, Cleaning, Component Replacement, Torque Specifications, Assembly, Troubleshooting Common Engine Issues, Engine Tuning (carburetor jetting, ignition timing where adjustable), Seal and Bearing Replacement, Crankshaft Balancing Checks

Technical Depth:

Comprehensive engine overhaul, detailed component-level repair, diagnostic information for common engine failures, precise assembly and torque specifications for critical components.

📊 Manual Specifications

File Format:

Print (Physical Book)

Print Quality:

Professional offset printing with clear diagrams and text (typical of original manufacturer manuals)

Binding Type:

Stapled or Perfect Bound (common for manuals of this page count)

Paper Type:

Matte or semi-gloss coated paper for durability and clarity of images

⚙️ Engine Specifications

Engine Type:

2-Stroke, Single Cylinder, Reed Valve Induction

Bore X Stroke:

Varies by displacement (e.g., 250cc: ~66.4mm x 72mm, 300cc: ~72mm x 72mm, 380cc: ~86mm x 66mm - exact figures in manual)

Cooling System:

Liquid-Cooled

Horsepower Range:

Approx. 45-60 HP (Varies by model and tuning, specific dyno charts may not be present, but provides base specs)

Torque Range:

Approx. 35-45 ft-lbs (Varies by model, specific figures in manual)

Carburetor Type:

Keihin PWK or similar (Specific sizes like 38mm common, detailed in manual)

Fuel Type:

Unleaded Gasoline with 2-stroke Oil Pre-mix (Specific ratio and octane rating in manual)

🔧 Transmission

Transmission Type:

6-Speed Manual Synchromesh

Clutch Type:

Wet Multi-Plate Clutch (Hydraulic actuation common on later models within range)

Gear Ratios:

Specific ratios for each gear will be detailed in the manual for respective models.

📐 Dimensions

Dry Weight:

Approx. 230-245 lbs (Varies by model variant, manual may not list exact dimension but engine weight for handling/rebuild is implied)

🛡️ Safety Features

Safety Ratings:

N/A (Motorcycles are not rated by standard automotive safety organizations like NHTSA or IIHS in the same manner)

Active Safety Features:

Disc Brakes (Front and Rear), High-Performance Suspension

Passive Safety Features:

Frame Integrity, Handlebar Design for control

💡 Technology Features

Infotainment System:

N/A (Basic motorcycle instrumentation: Speedometer, Odometer, Tachometer, basic warning lights)

Driver Assistance:

N/A (No electronic rider aids beyond basic engine and chassis design)

🔧 Maintenance

Top End Rebuild Interval:

Highly variable based on usage, but recommended every 50-100 hours of hard riding for optimal performance.

Oil Change Interval:

Transmission oil: Every 15-20 hours. Pre-mix oil is consumed during operation.

Transmission Fluid Type:

API GL-4 SAE 75W/80 or 75W/90 Gear Oil (Specific OEM or recommended aftermarket fluid details in manual)

Coolant Type:

Ethylene Glycol based antifreeze with water (50/50 mix recommended, specific type in manual)

2 Stroke Oil Type:

High-quality synthetic 2-stroke racing oil, specific recommendations in manual.

Common Issues:

Worn Piston Rings, Worn Crankshaft Bearings, Power Valve Sticking, Clutch Plate Wear, Gasket Leaks, Carburetor Clogging due to fuel quality or contamination.

Preventative Maintenance:

Regular air filter cleaning/replacement, correct oil/fuel mix, proper transmission oil changes, and inspecting spark plug condition.

📚 Vehicle History

Brand Heritage:

KTM, known as 'Ready to Race,' has a strong heritage in off-road and motocross racing, establishing a reputation for performance and durability.

Model Evolution:

The SX and MXC lines represent KTM's commitment to competitive motocross and enduro racing. This generation of 2-stroke engines was a refinement of earlier designs, focusing on increased power and reliability for demanding off-road use.

Production Years Covered:

1999, 2000, 2001, 2002

🏆 Awards & Recognition

Off Road Performance:

KTM models of this era were highly competitive and often achieved podium finishes and race wins in national and international motocross and enduro events.