Positioning:
The Yamaha TTR125 is a popular entry-level to intermediate dirt bike, known for its reliability and ease of use, making it a staple for trail riding and recreational off-road use. This manual caters to owners and technicians needing in-depth support for maintaining and repairing this specific model.
Competitors:
Competes with models like the Honda CRF125F, Kawasaki KLX125, and Suzuki DR-Z125.
Manual Value Proposition:
Offers comprehensive factory-level repair data, enabling users to perform all necessary maintenance and repairs, thus extending the lifespan and maintaining the performance of their TTR125.
Target Audience:
Yamaha TTR125 owners, independent repair shops, motorcycle technicians, and enthusiasts seeking detailed technical information.
Engine:
Detailed disassembly, assembly, inspection, and repair of all engine components, including top-end, bottom-end, valve train, lubrication system, cooling system (if applicable).
Fuel System:
Carburetor service, adjustment, and troubleshooting; fuel tank and line maintenance.
Ignition System:
Spark plug specifications, ignition timing, CDI unit, and related components.
Transmission:
Clutch operation, inspection, and service; gearbox disassembly, assembly, and inspection.
Chassis And Frame:
Frame inspection, steering head bearing service, swingarm pivot, and rear shock absorber.
Suspension:
Front fork disassembly, oil change, seal replacement, and inspection; rear shock absorber service.
Braking System:
Front and rear brake caliper service, master cylinder inspection, brake pad replacement, bleeding procedures, and cable adjustment (if applicable).
Wheels And Tires:
Tire inspection, pressure recommendations, spoke tensioning, wheel bearing service.
Electrical System:
Wiring diagrams, battery maintenance, lighting system, charging system (stator, rectifier/regulator), starter motor (if electric start equipped), and general troubleshooting.
Bodywork And Trim:
Fender removal/installation, seat maintenance, fuel tank removal/installation, and other external components.
Routine Maintenance:
Oil change intervals, air filter cleaning/replacement, spark plug checks, chain adjustment and lubrication, brake adjustments, bolt torque checks.
Troubleshooting:
Step-by-step diagnostic procedures for common performance issues, starting problems, and electrical faults.
Engine Overhaul:
Complete procedures for engine rebuilds, including piston and cylinder inspection/replacement, crankshaft service, and valve adjustments.
Transmission Repair:
Detailed instructions for clutch replacement, gearbox component inspection, and reassembly.
Suspension Service:
Fork seal replacement, oil level adjustments, rear shock absorber servicing.
Electrical Diagnostics:
Using multimeters for testing circuits, diagnosing charging system faults, and troubleshooting ignition issues.
Carburetor Tuning:
Jetting recommendations, idle speed adjustment, mixture screw settings.
Depth Of Information:
Comprehensive, covering everything from basic owner maintenance to full engine and transmission rebuilds. Suitable for professional mechanics and experienced DIY enthusiasts.
Diagnostic Charts:
Likely includes symptom-to-cause diagnostic charts for common problems.
Torque Specifications:
Detailed torque values for all critical fasteners across various systems.
Special Tools:
Identification and usage of specialized tools required for specific repair procedures.
Engine Type:
Four-stroke, SOHC, 2-valve
Bore X Stroke:
54.0 mm x 54.5 mm
Compression Ratio:
Approximately 9.5:1 to 10.5:1 (varies slightly by sub-model)
Horsepower:
Estimated 10-12 HP (at crank, varies by tuning and specific model variant)
Torque:
Estimated 7-8 lb-ft (at crank, varies)
Carburetor Model:
Mikuni VM20 (common for TTR125L/E models)
Fuel Type:
Unleaded gasoline (minimum octane rating specified in manual)
Ignition System:
CDI (Capacitor Discharge Ignition)
Spark Plug Type:
NGK CR8E (common, but verify with manual)
Transmission Type:
Constant mesh, 5-speed
Clutch Type:
Wet, multi-plate
Gear Ratios:
Specific ratios detailed in the manual (e.g., 1st gear, 2nd gear, etc.)
Final Drive:
Chain drive (sprocket sizes specified)
Transmission Oil Type:
Yamaha's recommended Yamalube 4 (or equivalent 4-stroke motorcycle oil, 10W-40 or 20W-40 often specified)
Transmission Oil Capacity:
Approximately 1.0 - 1.2 liters (check manual for exact capacity)
Engine Oil Change:
Every 1000 km (600 miles) or 6 months, whichever comes first (typical interval, check manual for exact recommendation).
Air Filter Cleaning:
Every 500 km (300 miles) or as needed, especially in dusty conditions.
Spark Plug Inspection:
Every 1000 km (600 miles).
Valve Clearance Check:
Every 4000 km (2400 miles) or annually.
Chain Lubrication And Adjustment:
Every 300 km (200 miles) or after washing/wet riding.
Engine Oil Specification:
API SG or higher, SAE 10W-40 or 20W-40 (refer to manual for precise viscosity and API rating based on ambient temperature).
Fork Oil Type:
Yamaha Suspension Fluid G10 (or equivalent 10W fork oil).
Common Wear Items:
Clutch plates, brake pads, chain and sprockets, wheel bearings, and fork seals are common wear items that may require replacement over time.
Carburetor Cleaning:
Carburetors can sometimes become clogged due to infrequent use or poor fuel quality, requiring periodic cleaning and adjustment.
Electrical Connections:
Corrosion on electrical connectors, especially in off-road environments, can lead to intermittent issues. Regular inspection and cleaning are recommended.
Heritage:
Yamaha has a long-standing reputation for producing reliable and capable off-road motorcycles, with a history dating back to the mid-20th century. The TTR line continues this legacy.
Ttr Line Introduction:
The TTR line was introduced to offer accessible and durable off-road motorcycles for various skill levels. The TTR125 specifically filled a niche for a lightweight, user-friendly trail bike.
Production Years:
The TTR125 series has been in production since the early 2000s, with various updates and sub-models (e.g., TTR125L for larger wheels/long travel suspension, TTR125E for electric start) introduced over the years.
