🏷️ Basic Information

Make:

Yamaha

Model:

TZ 125

Year:

1995

Model Code:

G1

Generation Identifier:

TZ 125 G1

Product Identifier:

1995 Yamaha TZ 125 G1 Service Repair Manual Download PDF

👋 Introduction

Vehicle Category:

Competition Motorcycle (125cc class)

Target Audience:

Yamaha TZ 125 racers, mechanics, and dedicated enthusiasts.

Competitors:

Other 125cc Grand Prix racing motorcycles of the era, such as Honda RS125, Aprilia RS 125, and Cagiva Mito 125 (though the TZ is purely competition-focused).

Manual Benefit 1:

Enables owners and technicians to perform complex repairs and maintenance efficiently.

Manual Benefit 2:

Provides in-depth understanding of the TZ 125's racing-specific technology.

Manual Benefit 3:

Facilitates accurate troubleshooting and problem diagnosis.

📋 Manual Details

Primary Focus:

Service and Repair

Estimated Page Count:

Varies based on specific revision, typically 200-400 pages for comprehensive service manuals.

Type:

Service Repair Manual

Language:

English

File Format:

PDF

📖 Manual Coverage

Engine Systems:

Engine overhaul, cooling system, carburetor, internal engine components (pistons, cylinders, crankshaft, connecting rods), lubrication, ignition system, exhaust system.

Chassis Systems:

Frame, suspension (front fork, rear shock absorber), steering, wheels, brakes (front and rear), chain drive, swingarm.

Electrical Systems:

Wiring diagrams, lighting, ignition system components, battery, charging system, controls, instrumentation.

Routine Maintenance:

Periodic inspection and adjustment, chain adjustment, brake adjustments, fluid checks and changes, spark plug maintenance.

Major Repairs:

Engine disassembly and reassembly, carburetor tuning and rebuilding, suspension overhaul, brake caliper service, electrical component troubleshooting and replacement.

Troubleshooting:

Diagnostic procedures for common problems, fault finding charts, symptom-based troubleshooting guides.

Diagnostic Level:

Advanced diagnostics and repair procedures for professional technicians and experienced enthusiasts.

Rebuild Instructions:

Detailed step-by-step instructions for complete engine rebuilds and major component overhauls.

Specifications Detail:

Comprehensive technical specifications, torque values, clearances, fluid capacities, and wear limits.

📊 Manual Specifications

File Type:

Portable Document Format (PDF)

Searchability:

Text-searchable PDF for quick information retrieval.

Resolution:

High resolution for clear viewing and printing.

Binding:

Digital Download (PDF) - No physical binding

Paper Quality:

N/A (Digital)

⚙️ Engine Specifications

Engine Type:

Two-stroke, liquid-cooled, single-cylinder

Bore X Stroke:

Typically around 54.0 mm x 54.5 mm (specific figures may vary slightly by year/variant)

Displacement:

124 cc

Compression Ratio:

High performance ratio, typically in the range of 12.0:1 to 14.0:1 or higher, depending on tuning.

Power Output:

Estimated 35-40+ HP (race-tuned, figures vary significantly with tuning and class regulations).

Torque Output:

Not typically quoted in standard manuals, but designed for high RPM power delivery.

Redline:

High, often exceeding 11,000 RPM, specific figure will be in manual.

Carburetor Type:

High-performance racing carburetor, e.g., Mikuni VM series or similar, with specific jetting and settings detailed in the manual.

Fuel Type:

High-octane racing fuel, often with specific octane rating requirements.

Fuel Delivery:

Gravity feed from fuel tank via carburetor.

🔧 Transmission

Transmission Type:

6-speed constant mesh

Gear Ratios:

Specific gear ratios are detailed in the manual and may vary based on race class regulations.

Clutch Type:

Wet multi-disc

Final Drive:

Chain drive

Transmission Fluid:

Specific gear oil specification will be listed in the manual, typically a high-quality transmission oil.

📐 Dimensions

Length:

Approx. 1,970 mm (specific figure in manual).

Width:

Approx. 660 mm (specific figure in manual).

Height:

Approx. 1,110 mm (specific figure in manual).

Wheelbase:

Approx. 1,350 mm (specific figure in manual).

Dry Weight:

Approx. 99 kg (specific figure in manual).

Fuel Tank Capacity:

Approx. 10 liters (specific figure in manual).

🛡️ Safety Features

Safety Classification:

Competition Motorcycle - Not intended or equipped for road use. Safety features are race-specific.

Braking System Front:

Hydraulic disc brake, dual piston caliper (specific caliper/rotor details in manual).

Braking System Rear:

Hydraulic disc brake, single piston caliper (specific caliper/rotor details in manual).

Frame Type:

Aluminum twin-spar frame for rigidity and light weight.

💡 Technology Features

Infotainment System:

N/A - Competition motorcycle focused purely on performance. No infotainment features.

Rider Aids:

N/A - No electronic rider aids. Purely mechanical and rider skill dependent.

Connectivity Features:

N/A - No connectivity features. Designed for track use only.

Ignition System:

CDI (Capacitor Discharge Ignition) with specific ignition timing curves detailed in the manual for optimal power delivery.

Exhaust System:

Expansion chamber exhaust system tuned for the 125cc 2-stroke engine's power band. Manual provides insights into its function.

🔧 Maintenance

Oil Change Frequency:

Dependent on racing usage; typically after a set number of race hours or competitive events. Specific recommendations in the manual.

Spark Plug Replacement:

Regular checks and replacement based on race conditions and performance. Manual will specify compatible plug types and heat ranges.

Engine Rebuild Interval:

Variable based on engine stress and usage; manual will guide on signs of wear and recommended rebuild points.

Coolant Type:

Ethylene glycol based, water-cooled coolant. Specific mix ratio and type provided in manual.

Brake Fluid Type:

DOT 4 or DOT 5.1 compatible hydraulic brake fluid. Manual specifies exact type and replacement intervals.

2-Stroke Oil Type:

High-quality, racing-grade 2-stroke oil for premix or oil injection system. Manual specifies recommended brands and viscosity.

Common Wear Items:

Piston rings, clutch plates, brake pads, chain and sprockets, wheel bearings, fork seals due to high-stress racing environment.

Carburetor Tuning:

Carburetor jetting and settings are critical for optimal performance and can require frequent adjustments based on track conditions, altitude, and fuel.

Engine Heat Management:

Proper cooling system maintenance is crucial for preventing overheating in high-performance 2-stroke engines.

📚 Vehicle History

Yamaha Motorsport:

Yamaha has a long and successful history in Grand Prix motorcycle racing, known for its innovative two-stroke engines and competitive chassis designs.

Tz Series Legacy:

The TZ series represented Yamaha's commitment to providing competitive 2-stroke machinery for privateer racers across various displacement classes, including the highly popular 125cc category.

Production Era:

The TZ 125 was produced and updated through multiple generations from the late 1970s through the early 2000s, with the G1 designation referring to the 1995 model.

🏆 Awards & Recognition

Racing Success:

The TZ 125 platform has been a highly successful platform in amateur and professional 125cc racing series worldwide, contributing to many championships for privateers.

Performance Rating:

Highly rated for its agility, precise handling, and competitive 2-stroke power delivery in its class.

Homologation:

While not road-legal, the TZ 125 was built to specific racing homologation standards for various series of its time.