| Specifications | RD125 (1973-1982) |
| Engine | Air-cooled 2-stroke single |
| Displacement | 123 cc (7.51 cu in) |
| Bore and stroke | 54 mm (2.13 in) x 54 mm (2.13 in) |
| Compression ratio | 7.5:1 |
| Power | 10 hp (7.5 kW) at 8,500 rpm |
| Torque | 7.8 lb⋅ft (10.6 N⋅m) at 7,000 rpm |
| Ignition | CDI |
| Carburetion | Mikuni VM22 |
| Clutch | Wet multi-plate |
| Transmission | 5-speed |
| Final drive | Chain |
| Frame | Single backbone |
| Suspension | Front: Telescopic fork, 35 mm (1.4 in) travel |
| Rear: Twin shocks, 80 mm (3.1 in) travel | |
| Brakes | Front: Drum |
| Rear: Drum | |
| Wheels | Front: 14 inches |
| Rear: 14 inches | |
| Tires | Front: 2.75-14 |
| Rear: 3.00-14 | |
| Seat height | 30.3 inches (770 mm) |
| Wheelbase | 54.3 inches (1,380 mm) |
| Rake and trail | 26° / 3.9 inches (99 mm) |
| Dry weight | 242 lb (109 kg) |
| Fuel capacity | 2.6 US gal (9.8 L) |
| Oil capacity | 3.0 US qt (2.8 L) |
| Gear ratios | 1st: 2.38 |
| 2nd: 1.66 | |
| 3rd: 1.25 | |
| 4th: 1.00 | |
| 5th: 0.86 | |
| Performance | |
| Test | Result |
| 0-60 mph | 10.5 seconds |
| Top speed | 80 mph (129 km/h) |
| Fuel economy | 55 mpg (23 kmpl) |
| Oil Details | |
| | Type | SAE 30 | | |
| | Capacity | 3.0 US qt (2.8 L) | |
Yamaha RD125 motorcycle
The RD125 was a more powerful version of the RD50. It was powered by a 125cc air-cooled engine that produced 10 horsepower. The RD125 was a popular choice for teenagers and young adults. It was a fun and fast bike, but it was also not very comfortable to ride for long periods of time.
Pros:
More powerful than the RD50
Fun and fast
Reliable and durable
Cons:
Not very comfortable to ride for long periods of time
Not a good choice for beginners