Classification:
Entry-level to mid-range street motorcycle, known for reliability and ease of use.
Target Audience:
Commuters, beginner riders, those seeking a simple and robust motorcycle.
Competitors:
Honda CB250N/Nighthawk 250, Yamaha SR250, Kawasaki EN500 (though larger, similar utilitarian market).
Features:
Singularly-focused, reliable 250cc engine; comfortable riding posture; disc front brake; electric start (on some models/years); durable construction.
Countries:
Global (primarily English-speaking markets)
Region:
North America, Europe, Asia
Pages:
Approx. 200-300 (estimate based on typical workshop manuals of this era)
Type:
Workshop Service Repair Manual
Engine:
Detailed overhaul procedures, component testing, specifications, troubleshooting for the 249cc 4-stroke engine.
Fuel System:
Carburetor (Mikuni VM34SS) disassembly, cleaning, adjustment, specifications, fuel pump operation.
Ignition System:
CDI system, spark plug specifications, timing adjustments, troubleshooting.
Transmission:
6-speed gearbox, clutch operation, disassembly, inspection, lubrication, torque specifications.
Drivetrain:
Chain drive maintenance, sprocket inspection, replacement procedures.
Suspension:
Front telescopic forks: disassembly, seal replacement, oil type and level specifications. Rear shock absorber adjustment and inspection.
Brakes:
Front disc brake: caliper disassembly, pad replacement, fluid type (DOT 3/4), bleeding procedures. Rear drum brake inspection and adjustment.
Electrical System:
Wiring diagrams, battery maintenance, starter motor, lighting system, charging system (alternator/stator), fuses.
Frame And Bodywork:
Chassis inspection, handlebar replacement, seat removal, fuel tank removal and installation, fender replacement.
Cooling System:
Air-cooled engine; maintenance focuses on fin cleaning and airflow.
Maintenance:
Routine checks, oil changes, filter replacements, chain lubrication and adjustment, brake adjustments, spark plug replacement.
Troubleshooting:
Diagnostic charts for common starting, running, and electrical issues.
Repair:
Step-by-step instructions for component disassembly, reassembly, and adjustment.
Overhaul:
Complete engine and gearbox rebuild procedures.
Inspection:
Detailed visual and functional inspection guidelines for all major components.
Depth:
Comprehensive, covering basic maintenance to complete engine and transmission rebuilds. Includes detailed torque specifications and tolerances.
Format Details:
PDF (Portable Document Format), often high-resolution scans of original factory manuals.
Searchability:
Likely text-searchable if digitally OCR'd, otherwise image-based.
Quality:
Variable, dependent on the source scan quality. Typically black and white line drawings and text.
Binding:
N/A (Digital Format)
Paper:
N/A (Digital Format)
Engine Type:
Air-cooled, 4-stroke, SOHC, single-cylinder
Displacement:
249 cc (15.2 cu in)
Bore X Stroke:
66.0 mm x 72.0 mm (2.60 x 2.83 in)
Horsepower:
Approx. 20-22 HP at 7,500 RPM (manufacturer specific variations)
Torque:
Approx. 19.5 Nm (14.4 lb-ft) at 6,000 RPM (manufacturer specific variations)
Carburetor:
1 x Mikuni VM34SS, constant velocity
Fuel Capacity:
14 Liters (3.7 US gal)
Oil Type:
SAE 10W-40 API SE or SF (specific manual recommendation is crucial)
Oil Capacity:
Approx. 1.7 Liters (1.8 US qt) with filter change
Transmission Type:
Constant mesh, 6-speed return type
Clutch Type:
Wet, multiple-disc
Gear Ratios:
Refer to specific manual for detailed ratios (e.g., 1st: 2.692, 2nd: 1.789, 3rd: 1.381, 4th: 1.125, 5th: 0.916, 6th: 0.750 - typical for the model)
Final Drive:
Sealed chain drive
Length:
Approx. 2,100 mm (82.7 in)
Width:
Approx. 800 mm (31.5 in) at handlebars
Height:
Approx. 1,115 mm (43.9 in) at seat
Wheelbase:
Approx. 1,420 mm (55.9 in)
Dry Weight:
Approx. 140 kg (309 lbs)
Wet Weight:
Approx. 150 kg (331 lbs) (estimated)
Weight Distribution:
Typical for a 250cc motorcycle, balanced for stability.
Safety Standards:
Meets relevant motorcycle safety standards of the era.
Braking System:
Hydraulic front disc brake, mechanical rear drum brake.
Lighting:
Halogen headlamp, taillight, turn signals.
Frame Construction:
Steel diamond frame for rigidity and durability.
Oil Change Interval:
Every 3,000-5,000 km (1,800-3,000 mi) or 6 months, whichever comes first (refer to manual for precise recommendation).
Air Filter Cleaning:
Inspect every 3,000 km (1,800 mi), clean or replace as needed.
Spark Plug Replacement:
Inspect at 3,000 km (1,800 mi), replace at 6,000-10,000 km (3,700-6,200 mi).
Chain Maintenance:
Clean and lubricate every 500-1,000 km (300-600 mi) and after riding in rain.
Valve Clearance Check:
Every 6,000-12,000 km (3,700-7,500 mi) (critical for single-cylinder engines).
Engine Oil:
SAE 10W-40 API SE/SF
Brake Fluid:
DOT 3 or DOT 4
Fork Oil:
Refer to manual, typically SAE 10W or equivalent.
Common Wear Items:
Clutch wear, carburetor jetting issues, fork seal leaks, ignition coil failure, cam chain noise.
Electrical Gremlins:
Corrosion in connectors, aging wiring harnesses can cause intermittent issues.
Engine Longevity:
Generally robust, but requires regular maintenance, especially valve adjustments, to maintain optimal performance and longevity.
Manufacturer History:
Suzuki Motor Corporation, established in 1909, a Japanese multinational corporation known for motorcycles, automobiles, and marine engines.
Gn Series Context:
The GN series represented Suzuki's offering in the lightweight, economical street motorcycle segment, building on established single-cylinder designs.
Predecessors Successors:
Successor to earlier 250cc single-cylinder models, paving the way for later variations and models in the lightweight class.
Production Period:
Launched in the early 1980s, with production continuing through various iterations into the early 2000s.
