🏷️ Basic Information Identification Make: Yamaha Model: RD250/RD350 Model Variants: DS7 (1972), R5C (1972), RD250 (1973), RD350 (1973) Years Covered: 1972, 1973 Codes Model Codes: DS7, R5C, RD250, RD350 👋 Introduction Market Position Vehicle Class: Performance-oriented, air-cooled, two-stroke parallel-twin motorcycles. Competitive Analysis Competitors: Suzuki GT series, Kawasaki H series, Honda CB series (two-stroke variants of the era). Key Features Engine Technology: Advanced porting (5-port and 7-port reed valve 'Torque Induction System'), Autolube oil injection. Performance Focus: Designed for sport riding and spirited performance, particularly the RD models. Manual Value Proposition Convenience: Instant download, no shipping costs, immediate access to critical repair data. 📋 Manual Details Coverage Areas Manual Coverage Scope: Comprehensive service and repair information for specific Yamaha motorcycle models. Page Count Total Pages: 113 Manual Type Manual Type: Repair Manual / Service Manual Language Language: English Format Format: Digital Download (PDF implied by description) 📖 Manual Coverage Systems Covered Powertrain: Engine, Transmission, Crankcase, Crankshaft, Clutch, Primary Drive, Kick Starter, Shifter, Tachometer Gear Fuel System: Carburetor, Air Cleaner, Autolube System (Separate Automatic Lubrication) Chassis And Suspension: Front Fork, Rear Cushion, Steering Head, Rear Arm, Fuel Tank Wheels And Brakes: Front Wheel (R5C, DS7, RD250), Front Wheel (RD350), Rear Wheel Disc Brake (RD350), Rear Wheel Sprocket, Tires, Tire Inflation Electrical System: Charging System, Ignition System Engine Design: Cylinder Porting (5-Port and 7-Port Reed Valve), Torque Induction System, Yamaha Reed Valve Operation Procedures Included Engine Disassembly And Assembly: Engine Removal, Cylinder Head, Cylinder, Piston, Piston Rings, Piston Pin, Crankcase Splitting, Crankshaft Installation/Removal, Bearing Removal Notes Drivetrain Maintenance: Clutch Removal/Installation, Primary Drive Gear, Drive Sprocket Replacement, Rear Wheel Sprocket Replacement Suspension And Steering Service: Front Fork Service, Rear Cushion Service, Steering Head Bearing Service Wheel And Tire Service: Wheel Removal/Installation, Tire Replacement, Tire Inflation Specifications Electrical Diagnostics And Repair: Charging System Servicing, Ignition System Troubleshooting and Repair Lubrication System Service: Yamaha Autolube System: Features, Oil Pump Handling, Oil Pump Maintenance Technical Depth Diagnostic Capabilities: Detailed troubleshooting guidance for engine, chassis, and electrical systems. Rebuild Completeness: Covers complete engine disassembly, inspection, and reassembly, as well as chassis component overhauls. Special Procedures: Specific instructions for cylinder porting analysis, torque induction system operation, and reed valve system. 📊 Manual Specifications File Format Digital Format: PDF (implied, suitable for instant download and digital delivery) Print Quality Document Quality: High-quality digital reproduction of original factory documentation. Binding Type Physical Binding: N/A (Digital Product) Paper Type Physical Paper: N/A (Digital Product) ⚙️ Engine Specifications Primary Engine Engine Type: Air-cooled, two-stroke, parallel-twin Engine Variants Rd250/Ds7/R5C: 247cc (approximate, based on bore increase for R5's) Rd350: 347cc (approximate, based on bore increase) Performance Power Delivery: Known for strong mid-range and top-end power delivery characteristic of performance two-strokes. Fuel System Carburetion: Dual Mikuni VM carburetors (specific size varies by model, typically 24-28mm). Lubrication Autolube System: Yamaha Autolube, a separate automatic lubrication system delivering premixed oil to the crankcase. Cooling System Cooling Method: Air-cooled Engine Design Features Reed Valve Induction: Utilizes a reed valve system for improved intake charge control and performance, especially in the 7-port 'Torque Induction' models. 🔧 Transmission Standard Gearbox Type: Constant mesh, 5-speed sequential manual transmission. Features Drive System: Chain drive to the rear wheel. Primary Drive: Gears (specific ratio differs between R5 and RD models due to performance tuning). 📐 Dimensions Exterior Wheelbase: Refer to specific model specifications within the manual; typically around 53-55 inches. Weights Dry Weight: Varies by model, generally in the range of 300-350 lbs (136-159 kg). 🛡️ Safety Features Ratings Crash Test Data: N/A (Historical motorcycle, no modern crash ratings apply). Active Features Braking System: Front: Disc brake (RD350), Drum brake (R5C, DS7, RD250). Rear: Drum brake. Passive Features Frame Construction: Steel cradle frame. 💡 Technology Features Infotainment Features: N/A (Basic motorcycle technology of the era). Driver Assistance Features: N/A Connectivity Features: N/A 🔧 Maintenance Service Intervals Oil Change Recommendations: Refer to manual for specific intervals for engine oil, gearbox oil (if applicable, though often premix is used for engine lubrication in two-strokes). Tune Up Intervals: Regular spark plug checks, carburetor adjustments, and chain lubrication are critical. Fluid Specifications Autolube Oil: Yamaha recommends specific 2-stroke engine oils designed for Autolube systems. Consult the manual for exact specifications and approved brands. Gearbox Oil: Yamaha recommends Yamalube gear oil or equivalent. Capacity and viscosity (e.g., SAE 80) typically specified. Known Issues Two Stroke Wear: Piston ring and cylinder wear is common due to high operating temperatures and stresses of two-stroke engines. Carburetor Tuning: Carburetors may require frequent adjustment due to atmospheric conditions and engine wear. Autolube System Reliability: The Autolube pump and its internal mechanisms can wear, potentially leading to under-lubrication if not maintained. Regular inspection and correct oil are key. Clutch Wear: Clutch wear is typical for performance motorcycles, requiring periodic adjustment and replacement of friction plates. 📚 Vehicle History Brand Heritage Yamaha Legacy: Yamaha's reputation...