Market Segment:
Lightweight sport motorcycle, popular for urban commuting and entry-level performance riding.
Competitors:
Competed with other lightweight sportbikes and naked bikes of its era from manufacturers like Kawasaki (e.g., Ninja 250), Suzuki (e.g., GS500), and Honda (e.g., CBR250).
Unique Selling Points:
Single-cylinder engine for torquey power delivery, lightweight chassis for agile handling, Yamaha's reputation for reliability and performance.
Intended User:
Owner's seeking to perform their own maintenance and repairs, independent repair shops, and enthusiasts looking for in-depth technical knowledge.
Coverage Areas:
General Information, Technical Specifications, Periodic Inspections and Adjustment, Engine Overhaul, Cooling System, Carburetor, Chassis, Electricals, Troubleshooting
Page Count:
Estimated 300-500 pages (typical for this era and type of manual)
Manual Type:
Factory Service Repair Manual
Engine Systems:
Engine mechanicals, cylinder head, piston, crankshaft, valve train, lubrication system, ignition system, starting system
Fuel System:
Carburetor(s) disassembly, cleaning, adjustment, fuel tank, fuel lines, fuel pump (if applicable)
Cooling System:
Radiator, cooling fan, thermostat, coolant hoses, water pump
Chassis Systems:
Frame, front suspension (forks), rear suspension (shock absorber, swingarm), steering system, wheels, tires, brakes (front and rear), clutch, drive chain
Electrical Systems:
Wiring diagrams, lighting system, battery, charging system (generator/alternator, regulator/rectifier), ignition system components, instrumentation, starting motor
Bodywork And Trim:
Information on fairings, seat, fuel tank cover, fenders, and related fasteners for removal and installation.
Maintenance Procedures:
Oil change, filter replacement, spark plug replacement, air filter cleaning/replacement, chain adjustment and lubrication, brake fluid flush, coolant flush, valve clearance adjustment, carburetor synchronization
Repair Procedures:
Engine disassembly and reassembly, carburetor rebuild, suspension fork servicing, brake caliper overhaul, clutch assembly replacement, electrical component troubleshooting and replacement
Troubleshooting Guides:
Diagnostic procedures for common engine, electrical, and chassis issues, fault codes (if applicable)
Diagnostic Procedures:
Systematic troubleshooting charts and flowcharts to identify causes of malfunctions and guide repairs.
Engine Rebuild Steps:
Detailed step-by-step instructions for complete engine disassembly, inspection of components, internal part replacement (pistons, rings, bearings, valves), and reassembly with correct clearances and torque.
Technical Depth:
Comprehensive, covering basic maintenance to complete engine and chassis overhauls, including detailed torque specifications and clearances
Wiring Schematics Detail:
Detailed wiring diagrams illustrating all electrical circuits, component locations, and wire colors for accurate diagnosis and repair.
Specifications Tables:
Comprehensive tables of all technical specifications, including dimensions, tolerances, torque values, fluid capacities, and electrical data.
Illustrations Diagrams:
Extensive use of exploded view diagrams, schematics, and photographic illustrations to clarify procedures and component identification.
Engine Type:
4-stroke, liquid-cooled, DOHC, single-cylinder
Displacement:
660 cc (approximate, specific model variant may vary slightly)
Bore X Stroke:
Refer to manual for exact specifications, typically around 100mm x 84mm for this class of engine.
Compression Ratio:
Refer to manual for exact specifications.
Horsepower:
Estimated 40-50 HP (at crankshaft, model dependent)
Torque:
Estimated 45-55 Nm (at crankshaft, model dependent)
Fuel Delivery:
Carburetor(s) (specific model and number of carburetors to be detailed in manual, likely a single large bore or dual carb setup).
Ignition System:
CDI (Capacitor Discharge Ignition), electronic advance
Lubrication System:
Wet sump, forced lubrication
Overall Length:
Refer to manual for exact specifications.
Overall Width:
Refer to manual for exact specifications.
Overall Height:
Refer to manual for exact specifications.
Dry Weight:
Refer to manual for exact specifications, likely in the 160-180 kg range.
Wet Weight:
Refer to manual for exact specifications.
Fuel Tank Capacity:
Refer to manual for exact specifications, typically 15-18 liters.
Oil Capacity:
Refer to manual for exact specifications (engine oil and transmission oil).
Instrumentation:
Analog speedometer, tachometer, odometer, trip meter, neutral indicator, high beam indicator, oil pressure warning lamp, turn signal indicators. Specific features may vary by market/trim.
Rider Aids:
No electronic rider aids like ABS or traction control typically found on models from this era.
Connectivity Features:
N/A (Motorcycle technology of this era was focused on mechanical and basic electrical systems).
Oil Change Interval:
Typically every 3,000-5,000 km or 6 months, refer to manual for precise interval and oil type.
Valve Adjustment Interval:
Typically every 10,000-20,000 km, refer to manual for precise interval and tolerance specifications.
Chain Maintenance Interval:
Lubrication and tension check recommended every 500-1000 km, or as needed based on riding conditions.
Engine Oil Type:
Yamaha recommends specific motorcycle-grade oils (e.g., Yamalube) with appropriate viscosity (e.g., 10W-40 or 20W-50) and JASO MA certification. Manual will specify exact grade and API classification.
Coolant Type:
Ethylene glycol-based antifreeze/coolant, typically a 50/50 mix with distilled water. Manual will specify exact type and mixture ratio.
Brake Fluid Type:
DOT 4 or DOT 5.1 recommended, refer to manual for exact specification and change interval.
Common Wear Items:
Clutch plates, brake pads, chain and sprockets, suspension seals, carburetor diaphragms can be common wear items depending on mileage and maintenance history.
Potential Engine Issues:
As with any single-cylinder engine, regular valve adjustments and proper cooling system maintenance are crucial to prevent premature wear or overheating. Carburetor issues (clogging, worn jets) can also occur with age and fuel quality.
