Segment:
Performance Racing Motorcycle
Usage:
Track days, club racing, high-performance riding.
Competitors 125Cc Class:
Honda RS125, Aprilia RS 125 (though TZ is more track-focused).
Engine Type:
High-revving two-stroke, liquid-cooled, single-cylinder.
Chassis Design:
Lightweight, race-bred chassis for exceptional handling.
Tuning Potential:
Designed for extensive tuning and modification for racing.
Suspension:
High-performance adjustable front forks and rear shock absorber.
Primary Coverage:
Workshop Service and Repair
Secondary Coverage:
Periodic Maintenance, Troubleshooting, Overhaul Procedures, Wiring Diagrams
Estimated Page Count:
Hundreds (as per description)
Type:
Workshop Service Manual / Repair Manual
Engine System:
Complete engine overhaul, tuning, carburetor, ignition system, cooling system (if applicable), lubrication.
Transmission System:
Gearbox inspection, maintenance, repair, clutch operation.
Chassis System:
Frame inspection, suspension (front and rear), steering, wheels, tires.
Electrical System:
Wiring diagrams, lighting, ignition, charging system, battery, instrumentation.
Braking System:
Brake caliper, master cylinder, brake lines, fluid replacement, adjustments.
Bodywork And Trim:
Fairings, body panels, seat, controls, exhaust system.
Carburetor System:
Detailed breakdown, adjustment, cleaning, and jetting information for Mikuni carburetors.
Fuel System:
Fuel tank, lines, fuel cock, carburetor.
Maintenance:
Regular scheduled maintenance, oil changes, filter replacements, chain adjustment, spark plug service.
Troubleshooting:
Diagnostic procedures for common and uncommon faults, symptom-based solutions.
Repair:
Step-by-step instructions for component disassembly, repair, and reassembly.
Overhaul:
Detailed procedures for engine, gearbox, and other major component rebuilds.
Engine Tuning:
Information on port timing, exhaust modifications, and ignition curve adjustments.
Diagnostics:
Systematic diagnosis of electrical and mechanical faults.
Depth:
Comprehensive, suitable for professional technicians and advanced DIY enthusiasts.
Detail Level:
Detailed diagrams, torque specifications, clearances, adjustment procedures.
Engine Type:
Liquid-cooled, 2-stroke, reed valve induction, single-cylinder
Bore X Stroke:
Typically around 56 mm x 50.7 mm (subject to specific TZ125 variant evolution).
Compression Ratio:
Variable, typically high for racing (e.g., 10.0:1 or higher).
Cooling System:
Liquid-cooled
Horsepower:
Estimated 30-40+ HP (depending on year, tuning, and exhaust).
Torque:
Not typically the primary focus for this class, but significant at high RPM.
Carburetor:
Mikuni VM series (e.g., VM28SS or similar high-performance variant).
Fuel Type:
High-octane gasoline, often mixed with two-stroke oil.
Ignition:
CDI (Capacitor Discharge Ignition), often with adjustable timing.
Length:
Approximately 1915 mm (varies slightly by year).
Width:
Approximately 690 mm (varies slightly by year).
Height:
Approximately 1050 mm (varies slightly by year).
Dry Weight:
Around 90-95 kg (highly dependent on year and specific race configuration).
Fuel Capacity:
Approximately 9.5 - 10.5 Liters.
Oil Change:
After every few race sessions or as specified for track use (pre-mix or oil injection system).
Spark Plug:
Regularly inspected and replaced based on plug type and usage.
Chain Adjustment:
Frequent checks and adjustments required due to high performance.
Engine Rebuild:
Typically performed after a set number of race hours or performance degradation.
Coolant:
High-quality motorcycle-specific coolant with anti-corrosion additives.
Transmission Oil:
Yamaha's recommended 2-stroke transmission oil or equivalent.
Brake Fluid:
DOT 4 or DOT 5.1, depending on specific brake system requirements.
Premix Ratio:
Specific ratio for two-stroke oil to gasoline as per manual or manufacturer recommendation.
Two Stroke Tuning:
Sensitivity to fuel quality, jetting, and environmental conditions.
Clutch Wear:
Can experience rapid wear under aggressive track use.
Engine Seals:
Regular inspection and replacement of crank seals are crucial.
Yamaha Racing Legacy:
Yamaha has a long and illustrious history in Grand Prix motorcycle racing, with the TZ series being a cornerstone of their 125cc and 250cc efforts.
Tz Lineage:
The TZ125 evolved from earlier Yamaha racing designs, becoming a dominant force in its class for many years.
Manufacturing Location:
Japan
Production Duration:
The TZ125 model line spanned several decades, with the G1 designation representing a specific period of its development.