| General information |
| Model: | Yamaha ST 125 |
| Year: | 1998 |
| Category: | Sport |
| Engine and transmission |
| Displacement: | 125.00 ccm (7.63 cubic inches) |
| Engine type: | Single cylinder |
| Stroke: | 2 |
| Power: | 36.00 HP (26.3 kW)) |
| Max RPM: | 11000 |
| Fuel system: | Carburettor. mikuni |
| Fuel control: | Port control |
| Ignition: | electronic |
| Starter: | Kick |
| Lubrication system: | oil injection |
| Cooling system: | Liquid |
| Gearbox: | 6-speed |
Transmission type final drive: | Chain |
| Clutch: | wet plate |
| Physical measurements |
| Dry weight: | 110.0 kg (242.5 pounds) |
| Chassis and dimensions |
| Frame type: | steel deltabox |
| Front Suspension: | rwu forks |
| Rear Suspension: | monoshock |
| Front brakes: | Single disc. twin piston caliper |
| Rear brakes: | Single disc. twin piston caliper |
| Exhaust system: | single expansion chamber and muffler |
| Speed and acceleration |
| Top speed: | 160.0 km/h (99.4 mph) |
| Power/weight ratio: | 0.3273 HP/kg |
| Other specifications |
| Fuel capacity: | 10.00 litres (2.64 gallons) |
| Fuel consumption pr. 10 km (6.2 miles): | 8.00 litres (2.11 gallons) |
| Color options: | purple/ silver |
| Comments: | made by Yamaha Thailand model code 4XC |