Market Segment:
Entry-level to mid-range dual-sport motorcycles, popular for off-road riding and light trail use.
Key Competitors:
Honda CR125R, Kawasaki KDX125, Suzuki RM125, KTM 125 EXC of similar eras.
Vehicle Appeal:
Known for its lightweight, agile handling, reliable two-stroke engine, and versatility for both on- and off-road use.
Cost Effectiveness:
Inexpensive way to maintain and repair the vehicle compared to professional shop rates.
User Base:
Targeted at both DIY enthusiasts and professional mechanics seeking detailed repair information.
Engine Mechanical:
Full coverage including disassembly, inspection, repair, and reassembly of engine components.
Engine Electrical:
Comprehensive details on ignition system, charging system, lighting, and starter motor.
Emission Control:
Specific information related to emission control systems for the applicable model years.
Fuel System:
Detailed coverage of carburetor system, fuel tank, fuel lines, and fuel pump operation.
Suspension System:
Front fork and rear monoshock suspension servicing, adjustments, and overhaul procedures.
Clutch System:
Maintenance, adjustment, and repair of the clutch assembly and actuation mechanism.
Transmission:
Coverage of the 6-speed manual transaxle, including gear inspection, shift mechanism, and lubrication.
Drivetrain:
Information on the final drive chain and sprockets, including maintenance and replacement.
Steering System:
Handlebar, steering stem bearing, and fork alignment servicing.
Brake System:
Front and rear brake system maintenance, including hydraulic fluid, pad replacement, and caliper servicing.
Body Interior Exterior:
Fairings, fenders, seat, fuel tank, and other body panel removal, installation, and repair.
Body Electrical:
Wiring harnesses, switches, controls, lighting, and instrument cluster diagnostics.
Restraint System:
While primarily a motorcycle, this might refer to user safety recommendations or specific components if applicable.
Preventive Maintenance:
Detailed schedules and procedures for regular servicing, lubrication, and inspections.
Troubleshooting:
Systematic diagnostic guides for identifying and resolving common operational issues.
Repair And Rebuild:
Step-by-step instructions for component removal, overhaul, repair, and reinstallation.
Electrical Diagnostics:
Includes wiring diagrams and procedures for diagnosing electrical faults.
Torque Specifications:
Precise torque values for all critical fasteners and bolts.
Special Tools:
Identification of any specific tools required for certain maintenance or repair tasks.
Depth Of Coverage:
Comprehensive, suitable for both novice DIY enthusiasts and experienced mechanics.
Diagnostic Capability:
Extensive troubleshooting sections for diagnosing a wide range of mechanical and electrical issues.
Printability:
Fully printable, allowing users to print specific pages or the entire manual.
Zoom Capability:
Yes, allows for zooming in and out of illustrations and diagrams.
Delivery Method:
Instant Download
Software Requirements:
Adobe PDF Reader
Compression Requirement:
WinZip or similar archive utility
Operating Systems:
Compatible with all versions of Windows and Mac OS
Engine Type:
2-stroke, reed valve, liquid-cooled
Bore X Stroke:
56.4 mm x 50.0 mm
Compression Ratio:
7.2:1 (typical)
Horsepower:
Approx. 20-22 HP @ 8000 RPM (variant dependent)
Torque:
Approx. 16-18 Nm @ 7000 RPM (variant dependent)
Carburetor Model:
Mikuni VM28SS (typical)
Fuel Type:
Unleaded gasoline with appropriate 2-stroke oil pre-mix or oil injection system.
Lubrication Type:
Yamaha's Autolube system (oil injection) or manual pre-mix.
Safety Focus:
The manual details safe operating procedures, maintenance for reliable braking and handling.
Braking System:
Front: Disc brake; Rear: Drum brake or Disc brake (variant dependent).
Lighting System:
Headlight, taillight, brake light, turn signals (where equipped).
Instrumentation:
Analog speedometer, tachometer, odometer, and indicator lights.
Rider Aids:
None in the modern sense; focus is on mechanical simplicity and rider control.
Electrical System:
12V DC electrical system for ignition, lights, and charging.
Oil Change Interval:
Refer to manual for specific recommendations based on usage, typically 3,000-5,000 km for gearbox oil.
Spark Plug Maintenance:
Regular inspection and replacement as per manual recommendations, crucial for 2-stroke performance.
Gearbox Oil Type:
Yamalube Gear Oil (or equivalent API GL-4, SAE 80W or 10W-30 transmission oil) - specific viscosity may vary.
Coolant Type:
Yamaha-specified coolant or a high-quality ethylene glycol-based coolant with corrosion inhibitors (typically a 50/50 mix).
Brake Fluid Type:
DOT 3 or DOT 4 hydraulic brake fluid.
Common Wear Items:
Clutch plates, piston rings, reed valves, steering head bearings, swingarm bearings, and fork seals.
Carburetor Tuning:
Carburetors can be sensitive to altitude and temperature changes; proper tuning is key for optimal performance.
Exhaust Port Fouling:
Common in 2-strokes, requires periodic cleaning of the exhaust port and power valve (if applicable).
Yamaha Legacy:
Yamaha Motor Company, established in 1955, has a rich history in motorcycle manufacturing, known for performance and innovation.
Dt Series Heritage:
The DT series, introduced in the late 1960s, was instrumental in popularizing off-road and dual-sport motorcycles globally.
Production Period:
The DT125R was a key model in Yamaha's dual-sport lineup during the late 1980s.
