Segment:
Lightweight/Mid-weight commuter and beginner-friendly motorcycle.
Key Competitors:
Honda CB250, Kawasaki Gpz250, Suzuki GS250.
Engine Character:
Torquey, reliable, single-cylinder engine known for its simplicity and ease of maintenance.
Design Philosophy:
Utilitarian design with an emphasis on reliability and practicality for everyday use.
Primary Coverage:
Comprehensive service, repair, maintenance, and troubleshooting for the Yamaha SR250 motorcycle.
Included Models:
Yamaha SR250 (all variants and years within its production run).
Estimated Page Count:
300-400
Manual Type:
Factory Service Manual (FSM)
Engine System:
Complete engine overhaul, tuning, carburetor, ignition, lubrication, cooling (air-cooled).
Transmission And Drivetrain:
Clutch, gearbox, final drive chain maintenance and adjustment.
Fuel System:
Carburetor disassembly, cleaning, adjustment, fuel tank, fuel lines.
Electrical System:
Ignition system, lighting, charging system (stator, rectifier/regulator), battery, wiring diagrams.
Braking System:
Front and rear brake pad replacement, caliper maintenance, brake fluid bleeding, drum brake adjustment.
Suspension System:
Front fork overhaul (oil change, seal replacement), rear shock absorber maintenance.
Wheel And Tire:
Wheel bearing replacement, tire pressure, spoke tension adjustment.
Frame And Bodywork:
General chassis inspection, fairing/panel removal and installation, seat.
Routine Maintenance:
Oil change intervals and specifications, filter replacement, chain lubrication and adjustment, spark plug replacement.
Troubleshooting:
Diagnostic charts for common starting, running, and electrical issues.
Engine Repair:
Piston removal/installation, valve adjustments, decarbonization, crankshaft inspection.
Carburetor Tuning:
Idle speed adjustment, mixture screw settings, jetting changes.
Electrical Diagnostics:
Wiring harness continuity checks, testing ignition coil, charging system output.
Fork Rebuild:
Complete front fork disassembly, seal and bushing replacement, oil specification and level.
Depth Level:
Professional-level diagnostic and repair procedures, suitable for experienced mechanics and advanced DIY enthusiasts.
Engine Type:
4-stroke, SOHC, air-cooled, single-cylinder.
Displacement:
249 cc (approx.)
Bore X Stroke:
74 mm x 58 mm (typical)
Compression Ratio:
9.5:1 (typical)
Horsepower:
Approximately 18-22 hp (varies by year/market).
Torque:
Approximately 19-21 Nm (varies by year/market).
Carburetor Type:
Mikuni VM series (e.g., VM28) or similar single carburetor.
Fuel Delivery:
Carburetor
Engine Oil Change:
Every 3,000-5,000 km or 6 months.
Valve Clearance Check:
Every 10,000-15,000 km.
Spark Plug Replacement:
Every 6,000-10,000 km.
Engine Oil Type:
Yamalube 4 (or equivalent SAE 20W-40 or 10W-40 motorcycle oil meeting API SG or higher).
Engine Oil Capacity:
Approx. 1.8 liters (with filter change).
Fork Oil Type:
Yamaha Fork Oil (or equivalent SAE 10W suspension fluid).
Brake Fluid Type:
DOT 3 or DOT 4 brake fluid.
Carburetor Fouling:
Common in older bikes with infrequent use; requires cleaning and rebuilding.
Cam Chain Wear:
Can lead to ticking noise; requires replacement if excessive.
Electrical Connection Corrosion:
Especially in the regulator/rectifier and wiring harness connectors; requires cleaning and dielectric grease.
Clutch Slippage:
Can occur with age and mileage; may require clutch plate replacement.
Yamaha Heritage:
Yamaha Motor Company, known for its musical instruments and later its extensive range of motorcycles, has a legacy of innovation and performance since its founding in 1955.
Sr Series Lineage:
Part of Yamaha's long-standing SR line, which emphasized simple, air-cooled, single-cylinder engines, starting with the iconic SR400/SR500.
Production Years:
Approximately 1980-1990s (with variations by market; exact end date can be complex).
