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.
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.
Engine Type:
2-stroke, Air-cooled, Twin-cylinder
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)
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)
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.