🏷️ Basic Information

Make:

Yamaha

Model:

TT-R125

Model Variant:

TT-R125(R), TT-R125LW(R)

Year:

2003

Oem Manual Code:

Not explicitly stated, but implies official Yamaha documentation.

👋 Introduction

Positioning:

The TT-R125 series is positioned as an entry-level to intermediate off-road/trail motorcycle, popular for its ease of use, reliability, and Yamaha's strong brand reputation in the powersports market.

Competitors:

Competes with models such as the Honda CRF100F/CRF125F, Kawasaki KLX125, and Suzuki DR-Z125. Known for its balance of performance and user-friendliness.

Model Variants:

The '(R)' likely denotes a standard model, while 'LW(R)' suggests a Long Wheelbase version, often with larger wheels (e.g., 19-inch front, 16-inch rear) for better rider comfort and stability, especially for taller riders.

Target Audience:

Beginner to intermediate youth riders, trail riders, and those seeking a capable and fun off-road machine.

📋 Manual Details

Primary Coverage:

Comprehensive service and repair for the 2003 Yamaha TT-R125(R) and TT-R125LW(R) models.

Estimated Page Count:

Typically 300-500 pages for this type of comprehensive service manual.

Type:

Service Repair Manual

Language:

English

Format:

Instant Download (Digital PDF)

📖 Manual Coverage

Engine:

Detailed diagnostics, disassembly, inspection, repair, and reassembly of the 125cc engine, including top-end, bottom-end, lubrication, and cooling systems.

Fuel System:

Carburetor tuning, cleaning, and overhaul; fuel tank, petcock, and fuel line servicing.

Ignition System:

CDI ignition system troubleshooting, component testing (stator, ignition coil), and spark plug specifications.

Transmission Drivetrain:

Clutch operation, inspection, and adjustment; gearbox disassembly and reassembly; chain and sprocket maintenance.

Chassis Frame:

Frame inspection for damage, steering head bearing service, and general chassis component checks.

Suspension:

Front fork (telescopic) disassembly, inspection, seal replacement, fluid type and level specifications; rear shock absorber inspection and adjustment.

Brakes:

Front and rear brake system servicing, including pad replacement, caliper inspection, brake fluid type (DOT 3 or DOT 4), bleeding procedures, and drum brake adjustment (if applicable).

Electrical System:

Wiring diagrams, lighting system service, battery maintenance and testing, fuse replacement, and basic electrical troubleshooting.

Cooling System:

Air-cooled engine, focused on heat dissipation through fins and airflow.

Bodywork Trim:

Plastic fender and tank cover removal and installation, seat removal, and handlebar adjustments.

Routine Maintenance:

Oil changes, air filter cleaning/replacement, spark plug checks, chain lubrication and adjustment, brake adjustments, and general inspections.

Troubleshooting:

Diagnostic flowcharts and common problem identification for engine, electrical, and chassis issues.

Engine Repair:

Top-end rebuild (piston, rings, cylinder), valve adjustment, camshaft timing, and bearing inspection.

Carburetor Overhaul:

Complete disassembly, cleaning, reassembly, and jetting adjustments.

Suspension Service:

Front fork seal replacement and oil changes; rear shock absorber adjustments.

Brake System Service:

Brake pad replacement, caliper maintenance, and brake fluid flush/bleed.

Electrical Diagnostics:

Component testing using multimeters, troubleshooting lighting and ignition circuits.

Wheel Tire Service:

Tire pressure checks, spoke tension adjustment, and general wheel bearing inspection.

Depth:

Comprehensive, covering everything from basic maintenance and rider adjustments to full engine and transmission rebuilds, electrical diagnostics, and suspension servicing.

Diagnostic Capability:

Advanced, with specific troubleshooting guides, symptom-to-cause analysis, and diagnostic specifications.

Repair Scope:

Complete disassembly and reassembly of all major mechanical and electrical components.

📊 Manual Specifications

Format:

Digital PDF

Searchability:

Typically searchable text within the PDF for quick access to information.

Printability:

Printable pages allowing for hard copy reference.

Quality:

Professional digital reproduction, ensuring clarity of diagrams, text, and images.

Binding:

N/A (Digital format)

Paper:

N/A (Digital format)

⚙️ Engine Specifications

Type:

Four-stroke, SOHC, air-cooled

Displacement:

124cc

Bore X Stroke:

54 mm x 54.5 mm

Compression Ratio:

9.5:1

Horsepower:

Estimated 10-12 HP (peak, varies slightly with tuning/emissions).

Torque:

Estimated 7-8 lb-ft (peak, varies).

Carburetor:

Mikuni VM20SS or similar 20mm constant-velocity carburetor.

Fuel Type:

Unleaded gasoline

Fuel Tank Capacity:

Approx. 1.6 gallons (6.1 Liters)

🔧 Transmission

Type:

5-speed constant mesh

Clutch:

Wet, multiple disc

Final Drive:

Chain drive

Transmission Options:

None (standard 5-speed)

Gear Ratios:

Specific ratios detailed within the manual, crucial for performance tuning.

Clutch Adjustment:

Lever and cable free play adjustment specifications provided.

📐 Dimensions

Length:

TT-R125: Approx. 73.8 inches (1875 mm); LW: Approx. 77.2 inches (1960 mm)

Width:

Approx. 31.7 inches (805 mm)

Height:

TT-R125: Approx. 43.1 inches (1095 mm); LW: Approx. 45.5 inches (1155 mm)

Seat Height:

TT-R125: Approx. 31.7 inches (805 mm); LW: Approx. 33.5 inches (850 mm)

Wheelbase:

TT-R125: Approx. 50.2 inches (1275 mm); LW: Approx. 51.8 inches (1315 mm)

Dry Weight:

TT-R125: Approx. 198 lbs (90 kg); LW: Approx. 205 lbs (93 kg)

Curb Weight:

Not specified, but significantly higher than dry weight due to fluids.

Maximum Load Capacity:

Not specified by manufacturer, but typical for recreational off-road use.

Ground Clearance:

TT-R125: Approx. 11.2 inches (285 mm); LW: Approx. 11.6 inches (295 mm)

🛡️ Safety Features

Safety Ratings:

As a non-street-legal off-road motorcycle, it does not undergo DOT or NHTSA safety ratings. Safety is primarily rider-dependent and due to the machine's design for off-road use.

Braking System:

Front: Hydraulic disc brake; Rear: Drum brake (on standard models) or Hydraulic disc brake (on some LW variants or later models - manual will clarify for 2003 specific)

Throttle Control:

Friction-type throttle limiter (often adjustable by dealer/owner for rider progression).

Frame Construction:

Steel semi-double cradle frame designed for off-road durability.

Handlebar Design:

Knuckle guards/hand guards are often standard or a common aftermarket addition for protection.

💡 Technology Features

Infotainment System:

None. This is a basic off-road motorcycle focused on performance and utility, not road-going features.

Driver Assistance Features:

None. Focus is on rider control and machine feedback.

Connectivity Options:

None.

Lighting System:

Basic headlight and taillight for visibility, typically powered by a small DC system or stator output. Manual covers bulb replacement and basic circuit checks.

🔧 Maintenance

Oil Change Interval:

Typically every 1,000 miles (1600 km) or 6 months, but consult manual for exact intervals and conditions.

Air Filter Cleaning:

Every 10-20 hours of riding or more frequently in dusty conditions. Manual specifies cleaning and re-oiling procedures.

Spark Plug Replacement:

Recommended inspection every 6 months or 1,000 miles; replacement intervals vary based on plug type and usage.

Valve Clearance Check:

Typically every 6,000 miles or annually. Manual provides exact specifications and adjustment procedures.

Chain Lubrication Adjustment:

Every 300-500 miles (500-800 km) or after washing/heavy use. Manual details proper tension.

Engine Oil Type:

Yamalube 4 (or equivalent SAE 10W-30, API SE, SF, SG type, JASO MA) motorcycle oil.

Engine Oil Capacity:

Approx. 1.0 Liters (1.1 US qt) when filter is not changed; 1.1 Liters (1.2 US qt) when filter is changed.

Brake Fluid Type:

DOT 3 or DOT 4 hydraulic brake fluid.

Fork Oil Type:

Yamaha Sus. Oil (or equivalent SAE 10W fork oil). Manual specifies volume.

Carburetor Fouling:

Common in off-road bikes due to infrequent use or poor fuel quality. Manual details cleaning and tuning.

Suspension Seals:

Front fork seal leaks can occur with heavy use or impacts. Manual provides replacement procedure.

Chain Wear:

Regular lubrication and adjustment are critical to prevent premature wear and stretching.

Throttle Cable Adjustment:

Proper free play is essential for safe operation; manual outlines adjustment.

📚 Vehicle History

Yamaha Offroad:

Yamaha has a long and storied history in motocross and off-road racing, dating back to the 1960s. The TT-R line builds upon this legacy, focusing on reliability and user-friendliness for recreational riders.

Tt-R Line:

The TT-R125 was introduced as a successor to earlier models like the YZ80/85 and TT-X series, offering a more approachable four-stroke engine for younger or less experienced riders. The LW (Long Wheelbase) variant was added to accommodate larger riders and provide increased stability.

Production Years:

The TT-R125 platform has been in continuous production for many years, with the 2003 model representing a specific iteration within its lifecycle.

Manufacturing Location:

Likely manufactured in Japan or at one of Yamaha's global production facilities.

🏆 Awards & Recognition

Awards And Recognition:

While specific awards for the 2003 model year might be scarce, the TT-R125 series has consistently been recognized by enthusiasts and publications as a top-tier, reliable, and fun entry-level off-road motorcycle, earning it a strong reputation in its class.

Reliability Ratings:

Yamaha is generally known for its excellent reliability, and the TT-R125 is a testament to this, often praised for its durability and low maintenance requirements when properly cared for.