Market Segment:
Entry-level to intermediate off-road motorcycle, popular for trail riding and recreational use.
Target Audience:
Beginner riders, youth riders, and those seeking a reliable and manageable trail bike.
Key Competitors:
Honda CRF150F/R, Kawasaki KLX140, Suzuki DR-Z125.
Vehicle Type:
Off-road motorcycle (dirt bike).
Engine Layout:
Single-cylinder, air-cooled, four-stroke.
Transmission Type:
Manual (clutch and gears).
Suspension Type:
Telescopic front forks, Monocross rear suspension.
Wheel Size Options:
Available in standard (LW) and long-wheelbase (L) configurations with different wheel sizes.
Primary Coverage:
Complete Service and Repair
Diagnostic Coverage:
Advanced diagnostics, troubleshooting, and repair procedures
Maintenance Coverage:
Scheduled maintenance, routine checks, and preventative care
Disassembly Reassembly:
Complete disassembly and reassembly of all major components and systems
Estimated Page Count:
Estimated 200-300 pages (typical for this type of manual)
Type:
Factory Service Manual / Repair Manual
Format:
Digital Download (PDF)
Engine:
Complete engine overhaul, including top-end, bottom-end, valve train, cooling system (if applicable), lubrication system, and ignition system.
Transmission:
Clutch system, gearbox inspection, maintenance, and repair, including gear shift mechanism.
Fuel System:
Carburetor service, fuel tank, fuel lines, and related components.
Electrical System:
Wiring diagrams, lighting system, ignition system, charging system (stator, rectifier/regulator), battery maintenance, and troubleshooting.
Chassis:
Frame inspection, front suspension (forks), rear suspension (shock absorber, linkage), steering system, and wheel bearings.
Brakes:
Brake system inspection, maintenance, and repair for both front and rear brakes (drum or disc depending on model variant).
Bodywork:
Plastic body panels, seat, fenders, handlebars, and related fasteners.
Routine Maintenance:
Oil changes, filter replacements, chain adjustment, tire pressure checks, spark plug service, air filter cleaning/replacement.
Troubleshooting:
Step-by-step diagnostic procedures for common and uncommon problems, symptom analysis, and fault code interpretation (if applicable).
Repair Overhaul:
Detailed instructions for component removal, inspection, repair, and reinstallation.
Specifications:
Torque specifications for all fasteners, clearances, fluid capacities, and electrical component values.
Depth:
Comprehensive, covering everything from basic owner maintenance to complete engine and transmission rebuilds.
Detail Level:
Detailed, with exploded views, diagrams, and step-by-step instructions.
Engine Type:
Four-stroke, SOHC, 2-valve
Bore X Stroke:
54 mm x 54.5 mm (typical, may vary slightly by source)
Compression Ratio:
9.5:1 (typical)
Cooling System:
Forced air cooled
Horsepower:
Approx. 10-12 HP (specific figures may vary by exact model and testing)
Torque:
Approx. 7-8 lb-ft (specific figures may vary)
Fuel Delivery:
Carburetor (likely Mikuni VM20 or similar for the era)
Fuel Type:
Unleaded gasoline
Fuel Tank Capacity:
Approximately 1.6 US gal (6.0 L)
Overall Length:
Varies by model variant (LW, LWE) - typically around 74 inches (1880 mm)
Overall Width:
Approximately 31.5 inches (800 mm)
Overall Height:
Approximately 45.5 inches (1155 mm)
Seat Height:
Varies by model variant (LW, LWE) - approximately 31.7 inches (805 mm) for LW, 33.5 inches (850 mm) for LWE
Wheelbase:
Varies by model variant (LW, LWE) - typically 50.2 inches (1275 mm) for LW, 51.8 inches (1315 mm) for LWE
Dry Weight:
Approximately 176 lbs (80 kg)
Wet Weight:
Approximately 194 lbs (88 kg)
Maximum Load:
Refer to manual for specific rider/cargo weight limits.
Crash Safety Ratings:
Not applicable (off-road vehicle, not subject to automotive crash testing standards).
Braking System:
Front: Drum brake; Rear: Drum brake (on most variants). Some later models might have disc brakes, but 2008 TT-R125 generally features drums.
Lighting:
Headlight, taillight/brake light, handlebar-mounted controls.
Frame Construction:
Steel semi-double cradle frame.
Safety Equipment:
Reinforced handlebars, handguards (optional/aftermarket).
Infotainment System:
N/A (This is a basic off-road motorcycle with no infotainment system).
Driver Assistance Features:
N/A (No electronic rider aids or driver assistance features are present).
Connectivity Options:
N/A (No connectivity features).
Starting System Type:
Kick start (standard on some models) and/or Electric start (standard on E models like TT-R125E, TT-R125LWE).
Engine Oil Change:
Every 600 miles (1000 km) or 6 months, whichever comes first. (Check manual for specifics).
Oil Filter Replacement:
Replace engine oil filter at every oil change.
Air Filter Cleaning:
Clean air filter every 100 miles (160 km) or more frequently in dusty conditions. Replace as needed.
Spark Plug Service:
Inspect and clean/gap spark plug every 600 miles (1000 km). Replace as needed.
Chain Adjustment:
Check and adjust chain slack every 300 miles (500 km).
Valve Clearance Check:
Inspect and adjust valve clearances every 2000 miles (3000 km) or 24 months.
Engine Oil Type:
Yamalube 4 or equivalent SAE 10W-40 API SG or higher.
Engine Oil Capacity:
Approximately 1.0 US qt (0.95 L) with filter change.
Brake Fluid Type:
DOT 3 or DOT 4 brake fluid (if equipped with disc brakes, though drums are more common).
Coolant Type:
N/A (air-cooled engine).
Common Wear Items:
Chain and sprockets, brake pads/shoes (depending on variant), tires, air filter, spark plug. Clutch plates can wear with aggressive use.
Engine Performance Issues:
Carburetor jetting issues can arise from altitude changes or modifications. Ignition coil failures are rare but possible. Starting issues can sometimes be linked to the starter motor or battery on E models.
Suspension Wear:
Fork seals can leak, and rear shock absorber performance may degrade over time with heavy use.
Electrical Issues:
Loose connections or corroded grounds can cause intermittent electrical problems, especially on older bikes. Battery maintenance is crucial for electric start models.
Heritage:
Yamaha has a long-standing history of producing reliable and capable off-road motorcycles, dating back to the mid-20th century. The TT-R line is a continuation of this legacy, focusing on accessible and fun trail bikes.
Evolution:
The TT-R125 was introduced as a successor to earlier Yamaha trail bikes, offering a more modern package with a four-stroke engine, electric start (on E models), and improved suspension. It has seen minor updates over the years, primarily in styling and some component refinements.
Manufacturing Location:
Japan (primarily), though final assembly or components may be sourced globally.
Production Years:
The TT-R125 model line has been in production for many years, with significant updates around the turn of the millennium and continuing through to the present day in various iterations.
Industry Awards:
While specific awards for the 2008 model may not be widely publicized, the TT-R125 series has consistently received positive reviews for its reliability, ease of use, and affordability in the trail bike category.
Owner Satisfaction:
Generally high owner satisfaction due to its durable construction and low maintenance requirements.
