| MODEL | YAMAHA XS-1B 650 1970 |
| Year | 1970 |
| Engine Type | Four stroke, parallel twin, SOHC, 2 valves per cylinder |
| Displacement / Capacity | 653 cc / 39.8 cu in |
| Bore X Stroke | 75 x 74 mm |
| Compression Ratio | 8.4:1 |
| Cooling System | Air cooled |
| Max Power | 39.5 kW / 53 hp @ 7200 rpm |
| Max Torque | 54 Nm / 5.5 kgf-m / 39.8 lb-ft @ 6800 rpm |
| Ignition | Battery, induction coil |
| Induction | 2x Mikuni BS38 carburettors |
| Start System | Kick |
| TRANSMISSION SPECS | |
| Lubrication | Wet sump |
| Gear Box | 5 speed |
| Clutch | — |
| Final Drive | Chain |
| CHASSIS SPECS | |
| Frame | — |
| Front Suspension | Telescopic forks |
| Rear Suspension | Dual shock absorbers |
| Front Brakes | Drum |
| Rear Brakes | Drum |
| DIMENSION SPECS | |
| Overall Length | 2175 mm / 85.6 in |
| Overall Width | 905 mm / 35.0 in |
| Overall Height | 1135 mm / 44.7 in |
| Seat Height | — |
| Wheelbase | 1410 mm / 55.5 in |
| Ground Clearance | 150 mm / 5.5 in |
| Dry Weight | 185 kg / 408 lb |
| Wet Weight | — |
| WHEEL SPECS | |
| Front Tyre | 3.50-19 |
| Rear Tyre | 4.00-18 |
| FUEL SYSTEM | |
| Fuel Capacity | 12.5 Litres / 3.3 US gal |
| Fuel Consumption | — |
| Top Speed | 185 km/h / 115 mph |
The XS-1B, second-series version of Yamaha's 650 twin, mechanically close to the original XS-1 on the published figures. Still drum-braked, with a Mikuni BS38 carburettor pair.
