Market Segment:
Entry-level to intermediate off-road trail riding and recreational use
Competitors:
Honda CRF100F/150F, Kawasaki KLX110/140, Suzuki DR-Z110/125
Target Audience:
Beginner riders, youth riders, trail enthusiasts
Utility:
Reliable, user-friendly, capable trail bike
Engine:
Detailed diagnostics, repair, and overhaul of the engine
Fuel System:
Carburetor adjustment, cleaning, and repair
Ignition System:
Ignition timing, component testing, and replacement
Electrical System:
Wiring diagrams, troubleshooting, lighting, starter, charging system
Drivetrain:
Clutch operation, chain drive maintenance, gearbox inspection
Suspension:
Front fork service, rear shock absorber maintenance and specifications
Brakes:
Front and rear brake system maintenance, adjustments, and component replacement
Cooling System:
Air-cooled engine thermal management and related components
Chassis And Frame:
Frame inspection, steering head bearing service
Bodywork And Trim:
Panel removal and installation, graphical decals
Routine Maintenance:
Oil changes, filter replacements, chain adjustments, spark plug checks
Troubleshooting:
Systematic diagnostic procedures for common and uncommon issues
Repair Procedures:
Step-by-step instructions for component disassembly, repair, and reassembly
Rebuilds:
Engine top-end and bottom-end rebuild instructions
Specifications And Torques:
Detailed torque values for all critical fasteners
Depth:
Comprehensive, from basic checks to complete engine rebuilds
Engine Type:
Air-cooled, four-stroke, SOHC, two-valve
Bore X Stroke:
54 mm x 54.5 mm
Compression Ratio:
9.5:1 (approximate)
Horsepower:
Approximately 10-12 HP (estimated)
Torque:
Approximately 7-8 lb-ft (estimated)
Carburetor:
Mikuni VM20SS or similar
Fuel Type:
Unleaded gasoline
Ignition:
CDI (Capacitor Discharge Ignition)
Starter:
Kick start (all variants), Electric start (E and LWE variants)
Length:
Approx. 1805 mm (71.1 in)
Width:
Approx. 770 mm (30.3 in)
Height:
Approx. 1060 mm (41.7 in)
Wheelbase:
Approx. 1270 mm (50.0 in) for standard, 1295 mm (51.0 in) for LW variants
Dry Weight:
Approx. 82 kg (181 lbs) for standard, 83 kg (183 lbs) for LW variants
Fuel Tank Capacity:
6.0 L (1.6 US gal)
Engine Oil Change:
Every 1000 km (600 miles) or 6 months, whichever comes first. Check more frequently under severe use.
Air Filter Cleaning:
Clean every 500 km (300 miles) or more often in dusty conditions. Replace as needed.
Spark Plug Check:
Check every 1000 km (600 miles). Adjust gap or replace as needed.
Valve Clearance Check:
Check every 4000 km (2500 miles).
Engine Oil Type:
Yamaha Genuine Oil 10W-40 SE Type or API SE, SF, SG classification or SAE 20W-40, 10W-30, or 5W-30.
Engine Oil Capacity:
0.90 L (0.95 US qt) without filter change, 1.00 L (1.05 US qt) with filter change.
Brake Fluid:
DOT 3 or DOT 4 brake fluid.
Carburetor Jetting:
May require adjustment based on altitude or aftermarket exhaust/air filter modifications.
Clutch Feel:
Clutch plates can wear over time, affecting engagement and requiring adjustment or replacement.
Chain And Sprockets:
Regular adjustment and lubrication are critical to prevent premature wear.
Manufacturer Legacy:
Yamaha Motor Company is a renowned Japanese manufacturer with a long history of producing high-quality motorcycles, including a strong presence in off-road and motocross segments.
Tt R Series Context:
The TT-R series represents Yamaha's line of recreational off-road motorcycles, designed for ease of use and versatility. The 125cc class is a popular entry point into off-road riding.
Production Period:
The TT-R125 has been in continuous production since its introduction, with variations and updates over the years, including the models covered in this 2005 manual.
