Positioning:
The Yamaha R5C was a significant model in Yamaha's sport motorcycle lineage, bridging the gap between earlier models and the iconic RD series. It was positioned as an accessible yet performance-oriented twin-cylinder two-stroke.
Competitors:
Competed against models like the Kawasaki H1 Mach III, Suzuki T500 Titan, and Honda CB350/CB400 Four, offering a unique blend of handling and torque characteristics.
Features:
Parallel-twin two-stroke engine, reed valve induction, disc front brake, lightweight chassis, sporty styling.
Engine:
Complete engine overhaul, tuning, carburetor, ignition, lubrication, cooling
Transmission:
Gearbox disassembly, assembly, inspection, lubrication
Frame And Suspension:
Frame inspection and repair, front forks, rear shock absorbers, swingarm, steering
Brakes:
Front and rear brake system maintenance, adjustment, component replacement
Electrical System:
Wiring diagrams, lighting, ignition system, charging system, battery
Fuel System:
Fuel tank, fuel lines, petcock, carburetor service
Exhaust System:
Exhaust pipes, mufflers, mounting
Wheels And Tires:
Wheel removal, installation, tire replacement, spoke adjustment
Bodywork And Trim:
Fenders, fuel tank, seat, handlebars, controls, emblems
Maintenance:
Regular scheduled maintenance, fluid changes, filter replacements, chain adjustment
Troubleshooting:
Diagnostic procedures for common and uncommon faults, symptom analysis
Repair:
Detailed step-by-step repair instructions for all major components and systems
Overhaul:
Complete engine and transmission rebuild procedures
Adjustment:
Carburetor synchronization, ignition timing, clutch and brake adjustments
Inspection:
Component wear assessment, safety checks
Depth:
Comprehensive, from basic adjustments to complete engine rebuilds and electrical system diagnostics
Type:
Air-cooled, two-stroke, parallel-twin
Displacement:
347 cc (approximate, depending on specific R5C variant)
Bore X Stroke:
54.0 mm x 74.0 mm (typical for R5 series)
Compression Ratio:
6.6:1 (typical)
Induction:
Reed valve induction
Horsepower:
Approximately 33 hp @ 7,000 rpm (estimated)
Torque:
Approximately 26 lb-ft @ 6,000 rpm (estimated)
Carburetors:
Dual Mikuni VM30SC (or similar 30mm units)
Fuel Type:
Unleaded gasoline (pre-mix oil required)
System:
Autolube (separate oil injection) and premix backup
System:
Contact breaker points, CDI ignition (later models/upgrades)
Identification:
Engine number typically found on the crankcase near the transmission.
Features:
N/A (no electronic infotainment features)
Features:
N/A (no electronic driver assistance features)
Features:
N/A (no electronic connectivity features)
Induction Type:
Reed valve induction for improved low-end torque and throttle response compared to piston port designs.
Brakes:
Introduction of a front disc brake was a significant advancement for improved stopping power over drum brakes.
Oil Change:
Check Autolube system regularly; gearbox oil change every 3,000-6,000 miles or annually.
Spark Plugs:
Inspect and clean/replace every 1,500-3,000 miles.
Chain Adjustment:
Check and adjust chain slack every 500 miles or as needed.
Carburetor Cleaning:
Recommended annually or if performance issues arise.
Air Filter:
Clean/replace every 3,000 miles or as per manual recommendation.
2 Stroke Oil:
Yamalube 2-stroke oil or equivalent JASO FD/FC rated oil.
Brake Fluid:
DOT 3 or DOT 4 (for disc brake caliper, check manual for specific type and replacement interval).
Ignition Systems:
Points ignition can be finicky; CDI upgrades are common. Worn points can cause misfires.
Carburetors:
VM30 carburetors can be prone to wear and require precise tuning. Diaphragm issues can cause poor performance.
Autolube System:
Oil pump drive or pump itself can fail, leading to engine seizure if not maintained. Always ensure oil reservoir is filled.
Engine Sealing:
Like many vintage two-strokes, crank seals can degrade over time, leading to air leaks and running issues.
Clutch:
Clutch plates can wear out, requiring replacement. Clutch adjustment is critical for smooth engagement.
Common Parts:
Manual will contain specific part numbers for engine components, seals, gaskets, electrical parts, etc.
Heritage:
Yamaha has a rich history in motorcycle manufacturing, known for innovation and performance, particularly in the two-stroke era.
Predecessors:
Evolved from earlier Yamaha parallel-twin models like the YDS series.
Successors:
Directly led to the highly successful Yamaha RD series (RD250, RD350, RD400).
Production Years:
1972-1973 (for R5C variant)
Manufacturing Location:
Japan
