🏷️ Basic Information Identification Make: Yamaha Model: RD400 (C) Year: 1976 Codes Model Code Rd250: RD250(C) Model Code Rd400: RD400(C) 👋 Introduction Market Position Vehicle Segment: Performance street motorcycles of the 1970s Competitor Segment: Direct competitor to other performance twin-cylinder motorcycles of the era Competitive Analysis Key Selling Points: Powerful two-stroke engines, agile handling, sporty aesthetics Key Features Manual Utility: Essential for owners and technicians performing maintenance and repairs Historical Significance: The RD series was a landmark in Yamaha's performance motorcycle development 📋 Manual Details Coverage Areas Manual Type: Service Repair Manual Page Count: 231 Language: English, French, German Format: PDF Delivery Method: Instant Download 📖 Manual Coverage Systems Covered Engine: Complete overhaul, tuning, troubleshooting Cooling System: Air cooling system specifications and maintenance Fuel System: Carburetor service, adjustment, and troubleshooting Chassis: Frame, suspension, wheels, brakes, steering Electrical: Ignition system, lighting, wiring diagrams, charging system Troubleshooting: Comprehensive diagnostic procedures for common issues Procedures Included Maintenance: Periodic inspections, adjustments, lubrication Repair: Engine rebuilds, component replacement, chassis repairs Diagnostics: Troubleshooting common problems with systematic approaches Technical Depth Level: Detailed mechanical and electrical repair procedures Scope: From basic maintenance to complete engine and chassis overhaul 📊 Manual Specifications File Format Type: PDF Compatibility: Windows/Mac Searchability: Likely text-searchable PDF (standard for professional manuals) Print Quality Recommendation: Printable for workshop use Binding Type Digital Equivalent: No physical binding, digital file Paper Type Digital Equivalent: N/A (digital format) ⚙️ Engine Specifications Primary Engine Rd250C Type: 247cc, air-cooled, two-stroke, parallel-twin Rd400C Type: 397cc, air-cooled, two-stroke, parallel-twin Rd250C Bore Stroke: 54.0 mm x 54.0 mm Rd400C Bore Stroke: 64.0 mm x 62.0 mm Rd250C Compression Ratio: 7.2:1 Rd400C Compression Ratio: 6.2:1 Performance Rd250C Horsepower: ~30 HP (estimated, actual figures vary by region/tune) Rd400C Horsepower: ~40 HP (estimated, actual figures vary by region/tune) Fuel System Carburetors Rd250C: Dual Mikuni VM26SC Carburetors Rd400C: Dual Mikuni VM28SC Fuel Type: Unleaded gasoline with 2-stroke oil pre-mix (specified ratio in manual) Engine Management Ignition System: CDI (Capacitor Discharge Ignition) 🔧 Transmission Standard Type: 6-speed, constant mesh, chain drive Optional Availability: N/A (standard configuration) Features Clutch: Wet, multi-plate Gear Ratios: Detailed in manual Transmission Fluid: Yamaha Gear Oil (specific grade detailed in manual) 📐 Dimensions Exterior Rd250C Dimensions: Refer to manual for exact dimensions (typical for period sportbike) Rd400C Dimensions: Refer to manual for exact dimensions (typical for period sportbike) Weights Rd250C Dry Weight: ~150 kg (estimated) Rd400C Dry Weight: ~157 kg (estimated) 🛡️ Safety Features Ratings Era Standards: Designed to meet 1970s motorcycle safety standards Active Features Brakes: Front: Disc brake; Rear: Drum brake (specifics detailed in manual) Suspension: Telescopic front fork, swingarm rear suspension with dual shock absorbers Passive Features Frame: Steel tubular frame for rigidity 💡 Technology Features Infotainment Era Context: N/A (technology focus was on mechanical performance) Driver Assistance Era Context: N/A (no electronic rider aids) 🔧 Maintenance Service Intervals Oil Change: Detailed in manual (typically based on mileage or time) Spark Plug Maintenance: Periodic inspection and replacement as per manual Carburetor Cleaning: As needed, detailed procedures in manual Fluid Specifications Two Stroke Oil: Specific blend ratios and oil types detailed in manual Brake Fluid: DOT 3 or DOT 4 (verify in manual) Known Issues Two Stroke Wear: Piston and cylinder wear common with high-mileage two-strokes, requires proper maintenance and lubrication Carburetor Tuning: Can be sensitive to altitude, temperature, and modifications; detailed tuning guides are crucial Electrical Connections: Corrosion or loose connections can affect ignition and lighting; periodic inspection recommended Part Numbers Filter Types: Specific oil filter, air filter, and spark plug part numbers are provided in the manual. 📚 Vehicle History Brand Heritage Yamaha Motorcycles: Yamaha has a long history of innovation in motorcycle design and performance, particularly with its two-stroke engines. Model Evolution Rd Series Legacy: The RD series, particularly the RD250 and RD350, established Yamaha's reputation for high-performance, lightweight, and nimble motorcycles. The RD400 was an evolution, offering increased displacement and power. Production Model Years: RD250: 1973-1975 (pre-C model), RD250(C): 1976. RD350 and RD400 models also existed. Manufacturing Location: Japan 🏆 Awards & Recognition Recognitions Model Impact: The RD series was widely acclaimed for its performance and handling, contributing significantly to Yamaha's sporting image in the 1970s. Ratings Contemporary Reviews: Received numerous positive reviews from motorcycle publications of the era for its speed and agility.