🏷️ Basic Information

Make:

Suzuki

Model:

GT 125

Model Variant:

GT125

Years Covered:

1974-1977

Engine Code Identifier:

GT125

👋 Introduction

Era Context:

The Suzuki GT 125 was part of Suzuki's popular GT series, known for its sporty styling and reliable performance in the 1970s commuter and light sportbike segment.

Competitors:

Competed against models like the Yamaha RD125, Kawasaki KH125, and Honda CB125S, offering a blend of performance and affordability.

Motorcycle Appeal:

Appealed to riders seeking an economical, stylish, and engaging motorcycle for daily commuting and recreational riding.

📋 Manual Details

Manual Type:

Service Repair Manual

Language:

English

Total Pages:

70+

File Format:

PDF (Assumed based on common digital manual distribution)

Print Quality:

High-resolution, clear diagrams and text (Assumed for quality manual)

Binding Type:

Digital Download (Assumed for sales business)

📖 Manual Coverage

Engine System:

Complete engine overhaul, disassembly, assembly, tuning, and troubleshooting.

Fuel System:

Carburetor service, adjustment, and troubleshooting; fuel tank and petcock maintenance.

Ignition System:

Ignition timing, spark plug specifications, coil and CDI unit testing.

Transmission System:

Gearbox disassembly and reassembly, clutch operation, and gear selection adjustments.

Chassis And Suspension:

Front fork service, rear shock absorber maintenance, swingarm inspection, steering head bearing service.

Braking System:

Front and rear brake adjustment, shoe replacement, drum brake service.

Electrical System:

Wiring diagrams, lighting system service, battery maintenance, charging system testing.

Exhaust System:

Exhaust pipe and muffler inspection and replacement.

Wheel And Tire Service:

Spoke tensioning, tire replacement, wheel balancing (basic).

Routine Maintenance:

Oil changes, filter replacements, chain lubrication and adjustment, spark plug replacement.

Troubleshooting:

Diagnostic charts for common running issues, starting problems, and performance issues.

Engine Rebuilding:

Piston and cylinder replacement, crankshaft inspection, gasket replacement.

Carburetor Tuning:

Idle speed adjustment, main jet and pilot jet selection based on conditions.

Electrical Diagnostics:

Use of multimeters for circuit testing, continuity checks.

Clutch Adjustment:

Cable adjustment for proper engagement and disengagement.

Brake Adjustment:

Lever and pedal free play, drum brake shoe adjustment.

Frame And Bodywork:

Frame inspection, fairing/panel removal and installation (if applicable), seat repair.

Coolingsystem Service:

N/A (Air-cooled engine)

Exhaust System Maintenance:

Inspection for leaks, gasket replacement, muffler repack (if applicable).

Steering Head Service:

Inspection and lubrication/replacement of steering head bearings.

Wheel Bearing Service:

Inspection and lubrication/replacement of wheel bearings.

Cable Replacement:

Throttle, clutch, and brake cable inspection, adjustment, and replacement.

Lighting System Repair:

Headlight bulb replacement, taillight repair, turn signal troubleshooting.

Depth Of Coverage:

Comprehensive; suitable for home mechanics and semi-professional use. Covers everything from basic maintenance to complete engine rebuilds and diagnostics.

📊 Manual Specifications

Digital Format:

PDF

Text Readability:

Clear and legible text for easy reading and comprehension.

Diagram Clarity:

High-resolution, detailed diagrams and exploded views for component identification and assembly guidance.

Delivery Method:

Instant Digital Download

Digital Paper Emulation:

Simulated glossy/matte paper texture for visual appeal in digital format.

⚙️ Engine Specifications

Engine Type:

2-stroke, Air-cooled, Twin-cylinder

Displacement:

125cc

Bore X Stroke:

43.0 mm x 43.0 mm (Typical for this model, verify in manual)

Compression Ratio:

7.5:1 (Typical, verify in manual)

Starting System:

Kick Starter

Horsepower:

16.5 PS @ 8,500 rpm (Approximate, model year dependent, verify in manual)

Torque:

1.3 kg-m @ 8,000 rpm (Approximate, model year dependent, verify in manual)

Carburetor:

Dual Mikuni VM18 (Typical, verify in manual)

Fuel Delivery:

Petcock operated, gravity feed

Fuel Type:

Unleaded gasoline (typically 91 octane or higher for 2-stroke mix)

2-Stroke Oil Mixing:

Autolube (Oil injection system) or Pre-mix (Specify in manual)

🔧 Transmission

Transmission Type:

6-speed Constant Mesh

Clutch Type:

Wet, Multi-plate

Gear Ratios:

Specific gear ratios detailed in manual.

Final Drive:

Chain Drive

📐 Dimensions

Overall Length:

1965 mm (Approximate, verify in manual)

Overall Width:

745 mm (Approximate, verify in manual)

Overall Height:

1070 mm (Approximate, verify in manual)

Dry Weight:

128 kg (Approximate, verify in manual)

Fuel Tank Capacity:

14 Liters (Approximate, verify in manual)

🛡️ Safety Features

Safety Standards:

Meets general safety standards of the era. Specific crash test ratings not applicable to this vintage motorcycle.

Braking System Type:

Front: Drum; Rear: Drum

Lighting:

Headlight, Taillight, Turn Signals, Brake Light

💡 Technology Features

Infotainment Features:

N/A - Analog gauges (speedometer, tachometer, odometer) and indicator lights.

Driver Assistance Features:

N/A - Focus is on mechanical and basic electrical systems.

Connectivity Options:

N/A

🔧 Maintenance

Oil Change Interval:

Refer to manual for specific interval based on mileage or time. Typically every 1,500-3,000 miles for 2-strokes or as per Autolube system recommendations.

Spark Plug Replacement:

Check and clean every 1,500 miles, replace every 6,000 miles (typical, verify in manual).

Chain Maintenance:

Lubricate and adjust every 500 miles or as needed. Replacement interval varies with use.

Engine Oil Type:

2-stroke specific oil (e.g., Yamalube, Castrol, Motul) mixed with gasoline or for Autolube reservoir. Verify specific viscosity grade (e.g., SAE 20W-40 for Autolube) in manual.

Transmission Oil Type:

Refer to manual for transmission oil specification and capacity. Typically SAE 80W or 90W gear oil.

Common Problems:

Carburetor clogging due to old fuel, CDI unit failure, piston ring wear, oil leaks from crank seals, ignition coil degradation.

Preventative Maintenance:

Regular cleaning of carburetors, checking ignition components, ensuring proper fuel mixture and oil levels, and chain lubrication are crucial.

📚 Vehicle History

Suzuki Heritage:

Suzuki has a long history of producing reliable and innovative motorcycles, starting with their early lightweight models and evolving into a major global manufacturer.

Gt Series Context:

The GT 125 was part of the GT (Grand Touring) series, which aimed to offer a blend of performance and comfort. It evolved from earlier Suzuki 125cc models, incorporating more modern styling and technology of the time.

Manufacturing Origin:

Japan

🏆 Awards & Recognition

Historical Reputation:

Suzuki's GT series models were generally well-regarded for their performance and value within their class during the 1970s.