Segment:
Entry-level to intermediate off-road/trail motorcycle.
Target Audience:
Youth riders, beginners, recreational trail riders, novice racers.
Competitors:
Honda CRF100F/150F, Kawasaki KLX125/140, Suzuki DR-Z125.
Engine Type:
Proven air-cooled 4-stroke, reliable and easy to maintain.
Suspension Variants:
TT-R125: Standard suspension. TT-R125L: Long-travel suspension, taller seat height, typically larger front wheel (21-inch vs 19-inch).
Ease Of Use:
Designed for accessibility and manageability for younger or less experienced riders.
Durability:
Known for Yamaha's reputation for robust and reliable components.
Primary Coverage:
Complete service and repair for the 2003 Yamaha TT-R125 and TT-R125L models.
Secondary Coverage:
Owner's information, routine maintenance, troubleshooting, and diagnostic procedures.
Type:
Service and Repair Manual (Dealership Level)
Engine:
Full coverage: teardown, assembly, inspection, tuning, troubleshooting of the 4-stroke air-cooled engine.
Fuel System:
Carburetor adjustment, cleaning, rebuilding, fuel lines, and tank servicing.
Ignition System:
CDI ignition, spark plug specifications, troubleshooting ignition failures.
Transmission Clutch:
Clutch operation, adjustment, replacement, gearbox inspection, and lubrication.
Suspension:
Front telescopic forks (TR125L: conventional, TR125/LE: USD option historically but this manual likely covers the base) and rear monoshock setup, oil changes, seal replacement, tuning.
Brakes:
Front disc brake, rear drum brake, hydraulic system, pad replacement, fluid bleeding, component inspection.
Electrical System:
Wiring diagrams, battery maintenance, lighting, switchgear operation, basic troubleshooting.
Chassis Frame:
Frame inspection, steering head bearing maintenance, swingarm and linkage servicing.
Wheels Tires:
Spoke tension adjustment, wheel bearing maintenance, tire selection and pressure recommendations.
Maintenance:
Regularly scheduled maintenance, oil changes, filter replacements, chain adjustment, bolt torquing.
Troubleshooting:
Systematic diagnostic approach for common performance issues and failures.
Repair:
Step-by-step instructions for component removal, repair, and reinstallation.
Rebuilds:
Detailed procedures for engine and carburetor rebuilds.
Specifications:
Torque values, clearances, fluid capacities, and critical measurements.
Depth:
Comprehensive: Covers everything from basic owner maintenance checks to full engine and transmission overhauls, mirroring dealership service procedures.
Engine Type:
4-stroke, SOHC, 2-valve, Air-cooled
Bore X Stroke:
54 mm x 54 mm
Horsepower:
Approximately 10-12 HP (estimated, actual varies by tuning and dyno)
Torque:
Approximately 7-8 lb-ft (estimated)
Carburetor Type:
Mikuni VM20SS (or similar 20mm slide carb)
Fuel Type:
Unleaded gasoline, minimum 87 octane
Oil Type Capacity:
Yamalube 4 (or equivalent SAE 10W-30) engine oil, 0.95 L (1.0 US qt) capacity.
Overall Length:
Approx. 1835 mm (72.2 in) for TT-R125L
Overall Width:
Approx. 765 mm (30.1 in) for TT-R125L
Overall Height:
Approx. 1070 mm (42.1 in) for TT-R125L
Seat Height:
Approx. 805 mm (31.7 in) for TT-R125L
Wheelbase:
Approx. 1260 mm (49.6 in) for TT-R125L
Dry Weight:
Approx. 77 kg (169.7 lbs)
Wet Weight:
Approx. 81 kg (178.6 lbs) with all fluids
Cargo Capacity:
N/A (Motorcycle)
Safety Certification:
Meets EPA emissions standards for off-highway vehicles.
Braking System:
Front hydraulic disc brake, rear drum brake for reliable stopping power.
Throttle Limiter:
Many models came with a throttle stop screw for speed control (refer to manual for adjustment).
Frame Construction:
Durable steel frame designed for off-road abuse.
Lighting:
Headlight and taillight for visibility (non-street legal configuration).
Engine Oil Change:
Every 1000 km (600 miles) or 6 months, whichever comes first. More frequently under severe use.
Air Filter Cleaning:
Every 500 km (300 miles) or every 3 months. Replace every 2 years or as needed.
Spark Plug Inspection:
Every 1000 km (600 miles).
Chain Lubrication Adjustment:
Every 200 km (125 miles) or after riding in wet conditions.
Valve Clearance Check:
Every 4000 km (2500 miles) or 24 months.
Engine Oil Spec:
SAE 10W-30 API SE, SF, SG or SH type engine oil.
Brake Fluid Spec:
DOT 3 or DOT 4 hydraulic brake fluid.
Carburetor Fouling:
Can be prone to dirt and debris accumulation; requires regular cleaning. Jetting may need adjustment for altitude or exhaust mods.
Suspension Seals:
Front fork seals can occasionally leak, especially under hard use. Rear shock can lose damping over time.
Clutch Cable:
May require adjustment or replacement due to stretching or wear.
Chain And Sprockets:
Wear out relatively quickly with aggressive off-road use; require frequent adjustment and lubrication.
Manufacturer:
Yamaha Motor Company, known for performance and reliability in motorcycles and other powersports vehicles.
Introduction Year:
The TT-R125 series was introduced in 1999.
Updates 2003:
The 2003 model year saw minor refinements but maintained the core design. Key differences between TT-R125 and TT-R125L are suspension travel and wheel size.
Manufacturing Location:
Primarily Japan, with some production possibly in other Yamaha facilities.
