Segment:
Entry-level to intermediate off-road sport motorcycle
Target User:
Beginner riders, youth riders, trail riding enthusiasts
Competitors:
Honda CRF150F, Kawasaki KLX140, Suzuki DR-Z125
Features:
Lightweight, easy to handle, reliable air-cooled engine, user-friendly operation
Manual Value:
Comprehensive factory repair data for maintaining peak performance and longevity
Engine:
Complete engine overhaul, tuning, diagnostics, lubrication
Fuel System:
Carburetor removal, cleaning, adjustment, specifications, fuel tank, petcock
Ignition System:
CDI, spark plug, ignition timing, troubleshooting
Transmission Drivetrain:
Clutch operation, gear shifting mechanism, chain adjustment, rear sprocket
Suspension Front:
Fork disassembly, reassembly, oil change, seal replacement, spring specifications
Suspension Rear:
Monoshock removal, reassembly, linkage lubrication, spring preload adjustment
Brakes Front:
Drum brake operation, adjustment, shoe replacement
Brakes Rear:
Drum brake operation, adjustment, shoe replacement
Wheels Tires:
Spoke tension, rim maintenance, tire pressure, mounting
Electrical System:
Wiring diagrams, lighting, horn, battery maintenance
Frame Chassis:
Frame inspection, tightening torque specifications, steering bearing maintenance
Exhaust System:
Muffler, header pipe removal and installation
Routine Maintenance:
Oil changes, filter replacements, chain lubrication, brake adjustments, spark plug checks
Troubleshooting:
Diagnostic flowcharts for common problems, symptom-based solutions
Component Repair:
Detailed step-by-step instructions for disassembly and reassembly of all major components
Overhaul:
Complete engine and transmission rebuild procedures
Adjustments:
Carburetor jetting, valve clearance, clutch, throttle, brake cables
Specifications Setting:
Torque values, clearances, fluid levels, tire pressures
Depth:
Factory-level diagnostic and repair procedures
Target Audience:
Professional technicians and experienced DIY mechanics
Type:
Four-stroke, SOHC, air-cooled
Displacement:
124 cc (7.57 cu. in.)
Bore X Stroke:
54 mm x 54 mm (2.13 in. x 2.13 in.)
Carburetor:
Mikuni VM20SS
Horsepower Estimate:
Approx. 11-13 HP (Actual figures vary by market and tuning)
Torque Estimate:
Approx. 7-8 lb-ft (Actual figures vary by market and tuning)
Fuel Type:
Unleaded gasoline
Fuel Tank Capacity:
4.0 L (1.06 US gal)
Oil Type:
Yamaha Genuine Oil API SG or higher, SAE 10W-30
Oil Capacity:
0.90 L (0.95 US qt) without oil filter change, 1.00 L (1.06 US qt) with oil filter change
Spark Plug Type:
NGK CR7E or Denso U22FS-U
Spark Plug Gap:
0.7 - 0.8 mm (0.028 - 0.031 in.)
Type:
Constant mesh 5-speed
Clutch Type:
Wet, multiple-disc
Primary Drive System:
Gear
Final Drive System:
Chain
Gear Ratios:
1st: 2.833, 2nd: 1.778, 3rd: 1.333, 4th: 1.045, 5th: 0.913
Transmission Oil Type:
Yamaha Genuine Gear Oil API GL-4, SAE 80W-90
Transmission Oil Capacity:
0.50 L (0.53 US qt)
Type:
Not Applicable (Off-road motorcycle, no standardized safety ratings like cars)
Braking System:
Drum brakes front and rear
Lighting:
Headlight, taillight, brake light
Ergonomics:
Designed for off-road control and rider comfort
Engine Oil Change:
Every 1,000 km (600 miles) or 6 months
Air Filter Cleaning:
Every 500 km (300 miles) or 3 months
Spark Plug Inspection:
Every 1,000 km (600 miles) or 6 months
Valve Clearance Check:
Every 4,000 km (2,500 miles) or 2 years
Chain Lubrication Adjustment:
Every 200 km (120 miles) or after washing/riding in rain
Brake Adjustment:
As needed, check at every 1,000 km (600 miles)
Engine Oil:
Yamaha Genuine Oil API SG or higher, SAE 10W-30
Transmission Oil:
Yamaha Genuine Gear Oil API GL-4, SAE 80W-90
Fork Oil Type:
Yamaha Genuine Fork Oil G10 or equivalent (e.g., SAE 10W)
Fork Oil Level:
135 mm (5.31 in.)
Common Wear Items:
Clutch plates, brake shoes, chain and sprockets, fork seals
Carburetor Performance:
Can be sensitive to jetting and altitude; requires periodic cleaning for optimal performance.
Suspension Performance:
Stock suspension can be soft for aggressive riding; fork oil changes are crucial for maintaining damping.
Heritage:
Yamaha has a long-standing reputation for producing durable and capable off-road motorcycles, with a history of success in motocross and enduro racing.
Predecessors:
The TT-R line evolved from Yamaha's earlier trail bikes, aiming to provide a user-friendly platform with modern features.
Evolutionary Changes:
The TT-R125 was a popular model that saw minor updates over its production run, focusing on reliability and ease of use. Later models introduced disc brakes and other refinements.
Production Period:
The TT-R125 was produced from the late 1990s through the mid-2000s.
Manufacturing Location:
Primarily Japan
