🏷️ Basic Information

Make:

Yamaha

Model:

TTR125 / TT-R125

Year:

2003

Engine Code:

4XM

Model Generation:

First Generation (pre-2008 redesign)

👋 Introduction

Market Segment:

Entry-level off-road/trail motorcycle, popular for youth riders and recreational trail riding.

Key Competitors 2003:

Honda XR100R/CRF100F, Kawasaki KLX125, Suzuki DR-Z125.

Model Highlights:

User-friendly, reliable, simple to maintain, suitable for learning and trail riding, electric start option available on some variants.

📋 Manual Details

Manual Coverage:

Complete Workshop Service and Repair

Estimated Page Count:

Approx. 300-400 pages (typical for this era and scope)

Manual Type:

Workshop Service Repair Manual

Language:

English

Format:

Downloadable Digital File (PDF)

📖 Manual Coverage

Engine Systems:

Top end (cylinder, piston, valves), bottom end (crankshaft, connecting rod, bearings), cooling system (air-cooled), lubrication system (oil pump, filter), fuel system (carburetor, fuel lines), ignition system (CDI, spark plug), exhaust system

Transmission Drivetrain Systems:

Clutch (automatic centrifugal), gearbox (5-speed constant mesh), final drive (chain, sprockets), shift mechanism

Chassis Suspension Steering Systems:

Frame, front forks (telescopic), rear suspension (monoshock), steering assembly (handlebars, triple clamps, steering stem bearings), swingarm

Brake Systems:

Front brake (drum), rear brake (drum), brake levers, cables

Electrical Systems:

Wiring diagrams, lighting system (headlight, taillight, brake light), ignition system components, battery, fuses, switches

Bodywork Fittings:

Body panels (fenders, shrouds, seat), footpegs, handlebars, levers, controls, plastics

Maintenance Procedures:

Oil changes, air filter cleaning/replacement, spark plug inspection/replacement, chain lubrication/adjustment, brake adjustment, valve clearance checks

Troubleshooting Procedures:

Diagnosis of common problems (starting issues, poor performance, electrical faults), symptom-based troubleshooting guides

Repair Procedures:

Engine disassembly and reassembly, carburetor overhaul, clutch inspection and replacement, suspension component service, brake system overhaul, electrical component testing and replacement

Disassembly Reassembly Procedures:

Step-by-step instructions for major component removal and installation

Technical Depth:

Comprehensive: Covers routine maintenance to complete engine and transmission rebuilds, including detailed diagrams and specifications.

📊 Manual Specifications

File Format:

PDF (Portable Document Format)

Print Quality Recommendation:

High resolution for clear text and diagrams, suitable for printing.

Binding Type For Print:

Spiral-bound or comb-bound recommended for lay-flat usability in a workshop environment.

Paper Type Recommendation:

Durable, grease-resistant paper for workshop use if printed.

⚙️ Engine Specifications

Engine Type:

4-stroke, SOHC, 2-valve, air-cooled single-cylinder

Displacement:

124 cc (7.58 cubic inches)

Bore X Stroke:

54.0 mm x 54.5 mm

Compression Ratio:

9.5:1 (typical for this model)

Estimated Horsepower:

Approx. 10-12 HP (at crankshaft, varies slightly)

Estimated Torque:

Approx. 7-8 lb-ft (at crankshaft, varies slightly)

Carburetor Model:

Mikuni VM20SS (typical specification)

Fuel Type:

Unleaded gasoline, minimum 87 octane

Oil Capacity:

Approx. 0.9 Liters (0.95 US qt)

Oil Type:

Yamalube 4 (or equivalent API SG, SAE 10W-40)

🔧 Transmission

Transmission Type:

5-speed constant mesh

Clutch Type:

Automatic centrifugal clutch

Gear Ratios:

Specific gear ratios available in the manual, typically: 1st: 2.500, 2nd: 1.750, 3rd: 1.333, 4th: 1.090, 5th: 0.913 (check manual for exact values)

Final Drive Ratio:

Typically 4.533 (49/11 teeth, check manual for variations)

Transmission Oil Type:

Yamalube 4 (or equivalent API SG, SAE 10W-40)

Transmission Oil Capacity:

Approx. 0.55 Liters (0.58 US qt)

📐 Dimensions

Overall Length:

Approx. 1830 mm (72.0 in)

Overall Width:

Approx. 795 mm (31.3 in)

Overall Height:

Approx. 1080 mm (42.5 in)

Wheelbase:

Approx. 1270 mm (50.0 in)

Ground Clearance:

Approx. 250 mm (9.8 in)

Seat Height:

Approx. 805 mm (31.7 in)

Dry Weight:

Approx. 79 kg (174 lbs)

Wet Weight:

Approx. 83 kg (183 lbs) (with all fluids)

Fuel Tank Capacity:

Approx. 5.7 Liters (1.5 US gal)

🛡️ Safety Features

Safety Certification:

Not applicable in the same manner as automobiles. Designed for off-road use.

Braking System:

Drum brakes front and rear for reliable stopping power suitable for off-road conditions.

Suspension:

Provides stable handling and absorbs terrain irregularities.

Frame Construction:

Robust steel frame designed for durability in off-road environments.

Tire Type:

Knobby tires for off-road traction and grip.

💡 Technology Features

Infotainment System:

Not applicable. Designed as a basic off-road machine with no electronic entertainment features.

Electronic Aids:

None. Focus is on mechanical simplicity and rider control.

Connectivity Features:

Not applicable.

🔧 Maintenance

Engine Oil Change Interval:

Every 1,000 km (600 miles) or 6 months (check manual for exact mileage/time for specific conditions)

Air Filter Cleaning Interval:

Every 500 km (300 miles) or as needed based on riding conditions (dusty environments require more frequent checks)

Spark Plug Inspection Interval:

Every 1,000 km (600 miles)

Valve Clearance Check Interval:

Every 5,000 km (3,000 miles) or annually

Engine Oil Grade:

SAE 10W-40

Engine Oil Standard:

API SG or higher, JASO MA certified

Brake Fluid Type:

DOT 3 or DOT 4 (for applicable systems, though this model uses drum brakes which typically don't require fluid)

Common Wear Items:

Tires, brake pads (if applicable), chain and sprockets, air filter, spark plug, clutch plates (due to automatic engagement).

Carburetor Maintenance:

Carburetors can become gummed up if the bike sits for extended periods without fuel stabilizer; regular cleaning and adjustment may be needed.

Suspension Wear:

Fork seals and rear shock absorbers can wear over time, leading to leaks or reduced damping performance.

📚 Vehicle History

Yamaha Motorcycle History:

Yamaha Motor Company, established in 1955, has a long and successful history in motorcycle manufacturing, known for innovation, performance, and reliability across various disciplines including off-road.

Ttr Series Introduction:

The TTR line was introduced to provide accessible and capable off-road motorcycles. The TTR125 specifically replaced smaller displacement models and offered a step up in performance and features for young riders and casual trail users.

Production Period:

The TTR125 has been in continuous production since its introduction, with significant updates occurring in later model years (e.g., 2008 redesign with larger wheels and disc brakes).

Manufacturing Location:

Primarily manufactured in Japan by Yamaha Motor Corporation.

🏆 Awards & Recognition

Industry Accolades:

While specific awards for the 2003 model are not widely documented, the TTR125 has consistently been recognized by the off-road community for its value, reliability, and suitability for its intended purpose as a beginner/intermediate trail bike.

Rider Reviews:

Generally rated highly by owners for its ease of use, low maintenance costs, and fun factor in trail riding scenarios.

Emissions Standards:

Designed to meet emissions standards relevant to its production year and market. Specific certifications would be detailed in official Yamaha documentation.