| MODEL | YAMAHA TX 650-III 1980 |
| Year | 1980 |
| Engine Type | Air cooled, four stroke, parallel twin cylinder |
| Displacement / Capacity | 653 cc |
| Bore X Stroke | 75 x 74 mm |
| Compression Ratio | 8.4:1 |
| Cooling System | Air cooled |
| Max Power | 50 hp @ 7500 rpm |
| Max Torque | 5.3 kgf-m @ 5500 rpm |
| Ignition | Battery powered inductive |
| Induction | 2 x Mikuni carburettors |
| Start System | — |
| TRANSMISSION SPECS | |
| Lubrication | — |
| Gear Box | 5 Speed |
| Clutch | — |
| Final Drive | Chain |
| CHASSIS SPECS | |
| Frame | — |
| Front Suspension | — |
| Rear Suspension | — |
| Front Brakes | 2 x 297 mm discs |
| Rear Brakes | Drum |
| DIMENSION SPECS | |
| Overall Length | — |
| Overall Width | — |
| Overall Height | — |
| Seat Height | — |
| Wheelbase | — |
| Ground Clearance | — |
| Dry Weight | 209 kg |
| Wet Weight | — |
| WHEEL SPECS | |
| Front Tyre | 3.50-19 |
| Rear Tyre | 4.00-18 |
| FUEL SYSTEM | |
| Fuel Capacity | 17 Litres |
| Fuel Consumption | 51 mpg |
| Top Speed | — |
The last of the 650 twins in this series had twin front discs and a larger 17-litre tank. Output was quoted at about 50 hp, a little below the earlier 53 hp claim. It still ran a two-carburettor air-cooled parallel twin and a five-speed chain-drive transmission.
