🏷️ Basic Information Identification Make: Yamaha Model: R5C Year: 1972, 1973 Codes Model Code: R5C 👋 Introduction Market Position Positioning: Performance-oriented twin-cylinder motorcycle of its era, targeted at enthusiasts and riders seeking spirited performance. Competitive Analysis Competitors: Competed with other 350cc to 400cc two-stroke motorcycles from manufacturers like Kawasaki, Suzuki, and Honda. Key Features Engine Type: Air-cooled, two-stroke, parallel-twin Performance Focus: Emphasis on lightweight design and strong acceleration characteristic of two-stroke engines. Design Era: Reflects the styling and engineering prevalent in Japanese motorcycles of the early 1970s. 📋 Manual Details Coverage Areas Coverage Type: Comprehensive Workshop Repair & Service Page Count Pages: 113 Manual Type Type: Workshop Service Manual Language Language: English Format Format: PDF Download 📖 Manual Coverage Systems Covered Engine: Engine assembly, disassembly, tuning, lubrication, cooling, fuel, ignition, exhaust Transmission: Clutch, gearbox operation, maintenance, troubleshooting Chassis: Frame, suspension (front and rear), steering, wheels, tires, brakes (front and rear drum) Electrical: Lighting system, ignition system, charging system, wiring diagrams, battery, instrumentation Bodywork: Body panels, fuel tank, seat, handlebars, fenders Procedures Included Maintenance: Routine maintenance, oil changes, filter replacements, chain adjustment, spark plug service Troubleshooting: Diagnostic procedures for common mechanical and electrical issues Repair: Detailed step-by-step instructions for component disassembly, repair, and reassembly Specifications: Torque specifications, clearances, fluid capacities, electrical resistance values Technical Depth Depth: Designed for mechanical technicians, covering in-depth repairs and diagnostics 📊 Manual Specifications File Format Format: Digital (PDF) Print Quality Quality: High-resolution scans suitable for printing Binding Type Binding: N/A (Digital Download) Paper Type Paper: N/A (Digital Download) ⚙️ Engine Specifications Primary Engine Engine Type: Two-stroke, air-cooled, parallel-twin Displacement: 347 cc (21.18 cubic inches) Bore X Stroke: 54.0 mm x 74.0 mm (2.13 in x 2.91 in) Compression Ratio: 6.8:1 Carburetion: Two (2) Mikuni VM30SC carburetors Ignition: CDI (Capacitor Discharge Ignition) Performance Horsepower: Approximately 33 HP @ 7,500 RPM (Manufacturer claimed) Torque: Not explicitly stated, but characteristic of its class for the era. Fuel System Fuel Type: Unleaded gasoline with 2-stroke oil mixture (e.g., 50:1 or 32:1 depending on oil quality and manufacturer recommendation). Fuel Tank Capacity: Approx. 2.6 US gallons (9.8 Liters) 🔧 Transmission Standard Type: Constant mesh, 5-speed Clutch: Wet, multiple disc Features Drive Type: Chain drive 📐 Dimensions Exterior Overall Length: Approx. 82.3 inches (2090 mm) Overall Width: Approx. 31.7 inches (805 mm) Overall Height: Approx. 46.3 inches (1175 mm) Weights Dry Weight: Approx. 348 lbs (158 kg) Wet Weight: Not explicitly specified, but would include oil, fuel, and battery weight. 🛡️ Safety Features Ratings Safety Standards: No formal crash ratings or safety certifications like modern vehicles; safety relied on rider skill and mechanical integrity. Active Features Brakes: Front and Rear Drum Brakes. Mechanical actuation via cables. Passive Features Lighting: Headlight, taillight, brake light, turn signals (depending on market specification). Frame Construction: Steel cradle frame designed for rigidity and handling. 💡 Technology Features Infotainment Features: N/A. This is a vintage motorcycle; technology features are limited to essential functions. Driver Assistance Features: N/A. No driver assistance systems. Connectivity Features: N/A. No electronic connectivity features. 🔧 Maintenance Service Intervals Oil Change: Refer to manual for specific engine oil change intervals based on mileage or operating hours. Typically every 2,000-3,000 miles or annually. Spark Plug: Regular inspection and cleaning/replacement recommended based on mileage (e.g., every 1,000-2,000 miles). Chain Maintenance: Frequent lubrication and tension adjustment is critical for longevity and performance. Fluid Specifications Engine Oil Type: Specific 2-stroke pre-mix oil suitable for air-cooled engines. Manual will specify viscosity and API classification, if applicable. Gearbox Oil: Yamaha Gear Oil 10W-30 or equivalent is commonly recommended for the transmission. Capacity: ~1.2 Liters. Brake Fluid: Not applicable, as drum brakes are mechanically actuated. Cable lubrication is required. Known Issues Two Stroke Wear: Typical for vintage two-strokes: piston ring wear, cylinder scoring, carbon buildup in ports and exhaust, reed valve wear. Carburetor: Carburetors (Mikuni VM30SC) can be prone to clogging, worn jets, and float issues if not maintained. Electrical System: Aging wiring harnesses, corroded connectors, and failing stator or rectifier can cause electrical gremlins. Clutch Slippage: Clutch plates can wear out, leading to slippage, especially with aggressive riding. 📚 Vehicle History Brand Heritage Heritage: Yamaha Motor Company, founded in 1955, rapidly established a reputation for high-performance motorcycles, particularly in the two-stroke segment. Model Evolution Predecessor: The R5C is an evolution of Yamaha's R5 series, building upon the R5 (1970-1972) which itself was an evolution of earlier models like the DS6. Distinguishing Features: The 'C' designation often signifies updates or minor revisions over previous iterations, potentially including styling or minor mechanical tweaks. Production Production Period: 1972-1973 Manufacturing Location: Japan 🏆 Awards & Recognition Recognitions Type: Not applicable in the modern sense. The R5C was well-regarded in its class for performance and handling, contributing to Yamaha's growing reputation.