| Attribute | Value |
| General |
| Production from | 2006 year |
| Make | Yamaha |
| Model | Yamaha XT 660 X |
| Category | Enduro / offroad |
| Engine and transmission |
| Engine type | Single cylinder, four-stroke |
| Valves per cylinder | Add |
| Fuel system | Injection |
| Engine details | Add |
| Displacement | 660 cm³ |
| Power | 34.5 kw |
| Max RPM | Add |
| Fuel consumption | Add |
| Cooling system | Liquid |
| Transmission type,final drive | Chain |
| Torque | 58.4 Nm |
| Bore | 100 mm |
| Stroke | 84 mm |
| Gearbox | Add |
| Greenhouse gases | Add |
| Fuel control | Single Overhead Cams (SOHC) |
| Emission details | Add |
| Driveline | Add |
| Ignition | TCI |
| Clutch | Wet, multiple disc |
| Lubrication system | Dry sump |
| Compression | 10.0:1 |
| Exhaust system | Add |
| Chassis |
| Front suspension | Telescopic fork |
| Rear suspension | Monocross with linkage |
| Front brakes | Single disc |
| Rear brakes | Single disc |
| Diameter | 245 mm |
| Frame type | Front suspension system |
| Front tyre | 90/90-21 |
| Rear tyre | 130/80-17 |
| Seat | Add |
| Wheels | Add |
| Front wheel travel | 225 mm |
| Rear wheel travel | 160 mm |
| Trail | Add |
| Rake (fork angle) | Add |
| Other |
| Battery capacity | Add |
| Starter | Electric |
| Color options | Add |
| Carrying capacity | Add |
| Light | Add |
| Instruments | Add |
| Electrical Voltage | Add |
| Dimensions |
| Wheelbase | 1,505 mm |
| Kerb weight | Add |
| Dry weight | 165 kg |
| Power/weight ratio | 0.2091 |
| Overall height | 1,230 mm |
| Overall length | 2,240 mm |
| Overall width | 850 mm |
| Seat height | 865 mm |
| Alternate seat height | Add |
| Ground clearance | 210 mm |
| Front percentage of weight | Add |
| Rear percentage of weight | Add |
| Performance |
| Top speed | Add |
| Acceleration 0-100 km/h | Add |
| Length | Add |
| Reserve fuel capacity | Add |
| Fuel capacity | 15 l |
| Oil capacity | Add |
| Width | Add |
| Height | Add |