Positioning:
Performance-oriented twin-cylinder motorcycle of its era, targeted at enthusiasts and riders seeking spirited performance.
Competitors:
Competed with other 350cc to 400cc two-stroke motorcycles from manufacturers like Kawasaki, Suzuki, and Honda.
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.
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
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
Depth:
Designed for mechanical technicians, covering in-depth repairs and diagnostics
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)
Carburetion:
Two (2) Mikuni VM30SC carburetors
Ignition:
CDI (Capacitor Discharge Ignition)
Horsepower:
Approximately 33 HP @ 7,500 RPM (Manufacturer claimed)
Torque:
Not explicitly stated, but characteristic of its class for the era.
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)
Overall Length:
Approx. 82.3 inches (2090 mm)
Overall Width:
Approx. 31.7 inches (805 mm)
Overall Height:
Approx. 46.3 inches (1175 mm)
Dry Weight:
Approx. 348 lbs (158 kg)
Wet Weight:
Not explicitly specified, but would include oil, fuel, and battery weight.
Safety Standards:
No formal crash ratings or safety certifications like modern vehicles; safety relied on rider skill and mechanical integrity.
Brakes:
Front and Rear Drum Brakes. Mechanical actuation via cables.
Lighting:
Headlight, taillight, brake light, turn signals (depending on market specification).
Frame Construction:
Steel cradle frame designed for rigidity and handling.
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.
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.
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.
Heritage:
Yamaha Motor Company, founded in 1955, rapidly established a reputation for high-performance motorcycles, particularly in the two-stroke segment.
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 Period:
1972-1973
Manufacturing Location:
Japan
