Category:
Entry-level off-road/trail motorcycle.
Target Audience:
Beginner riders, youth riders, recreational trail riders, motocross enthusiasts.
Key Competitors:
Honda CRF150F, Kawasaki KLX140, Suzuki DR-Z125.
Design Philosophy:
User-friendly, reliable, and capable for off-road exploration and learning. Known for its balance and ease of use.
Variant Differences:
LW variant typically indicates a Long Wheelbase model, often with a lower seat height and potentially different suspension settings for stability or smaller riders.
Engine:
Detailed disassembly, assembly, inspection, and repair of the entire engine, including top-end (cylinder, piston, valves), bottom-end (crankshaft, connecting rod, bearings), timing system, cooling system (if applicable, though typically air-cooled for this model), lubrication system.
Fuel System:
Carburetor adjustment, cleaning, and overhaul; fuel tank inspection and cleaning; fuel line routing and inspection.
Transmission:
Clutch operation, adjustment, and replacement; gearbox disassembly, inspection, and reassembly; gear selection mechanism.
Chassis:
Frame inspection and repair; suspension system (front forks, rear shock absorber) disassembly, service, and adjustment; steering system inspection and maintenance.
Brakes:
Front and rear brake system inspection, maintenance, and repair (likely drum brakes for this era/model); brake cable adjustment and replacement.
Electrical System:
Ignition system (spark plug, CDI unit, stator); lighting system (headlight, taillight, brake light); wiring diagrams; battery maintenance and testing; troubleshooting electrical faults.
Bodywork And Trim:
Body panel removal and installation; seat; fenders; handlebars; control levers.
Routine Maintenance:
Oil changes, filter cleaning/replacement, spark plug checks and replacement, air filter cleaning/replacement, chain adjustment and lubrication, brake adjustments, tire pressure checks.
Troubleshooting:
Diagnostic charts for common problems, symptom-based troubleshooting, fault identification.
Repair And Rebuild:
Step-by-step instructions for component disassembly, cleaning, inspection for wear, repair procedures, and reassembly with torque specifications.
Adjustments:
Carburetor idle and mixture, clutch, throttle cable, brake cables, chain tension.
Torque Specifications:
Detailed torque values for all critical fasteners and components.
Depth:
Comprehensive, covering everything from basic owner maintenance to full engine rebuilds and component-level diagnostics. Suitable for amateur and professional mechanics.
Type:
4-stroke, SOHC, 2-valve, Air-cooled
Bore X Stroke:
54.0 mm x 54.5 mm (typical for this engine)
Compression Ratio:
9.5:1 (typical)
Horsepower:
Approx. 10-12 HP (estimated, actual figures vary with tuning and conditions)
Torque:
Approx. 7-8 lb-ft (estimated)
Carburetor Type:
Mikuni VM24 (typical for this model/year)
Fuel Type:
Unleaded gasoline, 87 octane or higher.
Oil Type:
Yamalube 4 (or equivalent motorcycle-specific 4-stroke engine oil) SAE 10W-30 or 20W-40 depending on ambient temperature. Refer to manual for exact specification.
Overall Length:
Approx. 1840 mm (TTR125) / 1900 mm (TTR125LW) (typical)
Overall Width:
Approx. 800 mm (typical)
Overall Height:
Approx. 1120 mm (TTR125) / 1155 mm (TTR125LW) (typical)
Seat Height:
Approx. 805 mm (TTR125) / 785 mm (TTR125LW) (typical)
Wheelbase:
Approx. 1295 mm (TTR125) / 1340 mm (TTR125LW) (typical)
Dry Weight:
Approx. 92 kg (TTR125) / 95 kg (TTR125LW) (typical)
Fuel Tank Capacity:
Approx. 6.0 liters (1.6 gallons)
Oil Capacity:
Approx. 1.0 liter (0.26 gallons) without filter change; 1.1 liter (0.29 gallons) with filter change. Refer to manual.
Front Tire Size:
80/100-21 51M (typical)
Rear Tire Size:
100/100-18 59M (typical)
Wheel Type:
Spoked wheels
Safety Certification:
CE, EPA (for street-legal configurations where applicable, though primarily an off-road model).
Handling:
Designed for stable and predictable handling, crucial for off-road riding.
Braking System:
Standard drum brakes front and rear, providing adequate stopping power for the model's performance class. Manual details proper adjustment and maintenance.
Lighting:
Includes headlight, taillight, and brake light for visibility and signaling.
Engine Oil Change:
Every 1000 km (600 miles) or 6 months, whichever comes first. Refer to manual for precise interval and conditions.
Air Filter Cleaning:
Every 1000 km (600 miles) or more frequently in dusty conditions. Refer to manual.
Spark Plug Check:
Every 1000 km (600 miles).
Chain Lubrication And Adjustment:
Every 500 km (300 miles) or after washing/riding in wet conditions.
Valve Clearance Check:
Every 6000 km (3600 miles).
Engine Oil Grade:
SAE 10W-30 or 20W-40 (Yamalube 4 or equivalent API SE, SF, SG, SH, SJ or higher)
Brake Fluid:
DOT 3 or DOT 4 brake fluid (if hydraulic brakes were equipped, though this model typically uses cables for drum brakes).
Grease:
Lithium-based multi-purpose grease (for bearings, pivot points).
Common Wear Items:
Clutch plates, brake shoes, chain and sprockets, wheel bearings, fork seals due to off-road use.
Carburetor Tuning:
Can require periodic adjustment for altitude or temperature changes. The manual provides correct procedures.
Suspension Performance:
Stock suspension may be soft for aggressive riding, but is adequate for trail use. Manual covers adjustment procedures.
Manufacturer Focus:
Yamaha is renowned for its performance motorcycles across various disciplines, including off-road, sportbikes, and cruisers. They have a long history of innovation and reliability.
Predecessors:
The TTR line evolved from Yamaha's successful dirt bike heritage, aiming to provide a more accessible and user-friendly platform for trail riding and beginner competition.
Development Focus:
The TTR125 was developed to be a versatile, air-cooled, 4-stroke machine that was easy to maintain and operate, bridging the gap between smaller pit bikes and larger, more complex off-road motorcycles.
Production Period:
The TTR125 was in production for many years, with the 2001 model being an early iteration of this popular platform.
