| MODEL | YAMAHA YDS-3C 1966 - 1967 |
| Year | 1966 - 1967 |
| Engine Type | Two stroke, piston-port, parallel twin |
| Displacement / Capacity | 247 cc / 15.0 cu in |
| Bore X Stroke | 56 x 50 mm |
| Compression Ratio | 7.5:1 |
| Cooling System | Air-cooled |
| Max Power | 24 hp @ 7500 rpm |
| Max Torque | 18.1 ft-lb / 4.2 kgf-m @ 7500 rpm |
| Ignition | Coil ignition |
| Induction | 2x Mikuni VM24SC with air filter |
| Start System | Kick |
| TRANSMISSION SPECS | |
| Lubrication | — |
| Gear Box | 5 Speed |
| Clutch | Wet, multi-plate, mounted on left side of crankshaft |
| Final Drive | Chain |
| CHASSIS SPECS | |
| Frame | — |
| Front Suspension | Telescopic forks with hydraulic damping |
| Rear Suspension | Dual shocks swinging arm, spring-and-hydraulic units with three-position adjustment for load |
| Front Brakes | Drum |
| Rear Brakes | Drum |
| DIMENSION SPECS | |
| Overall Length | 2006 mm / 79 in |
| Overall Width | 792.5 mm / 31.2 in |
| Overall Height | 1066.8 mm / 42 in |
| Seat Height | — |
| Wheelbase | 1470.5 mm / 51.9 in |
| Ground Clearance | — |
| Dry Weight | — |
| Wet Weight | 145 kg / 320 lbs |
| WHEEL SPECS | |
| Front Tyre | 3.00-18 |
| Rear Tyre | 3.25-18 |
| FUEL SYSTEM | |
| Fuel Capacity | 11.4 Litres / 3.0 gal |
| Fuel Consumption | — |
| Top Speed | — |
The YDS-3C was the final development of the 1960s 250 cc YDS sports twin, with the same air-cooled piston-port two-stroke engine and five-speed gearbox as the YDS-3. It was a light, quick sports roadster.
