The Yamaha YAS 1 motorcycle specifications include a 125 cc (7.63 cu in) engine, a 5-speed gearbox, and a listed weight of 105 kg (231.5 lb).
Key specifications
How the Yamaha YAS 1 compares
This compares the motorcycle with all Yamaha models in this specifications database. The blue marker is this model and the grey line is the Yamaha database average.
About 77% lower than the Yamaha database average. Around the 25th percentile across Yamaha models.
About 44% lighter than the Yamaha database average. Around the 14th percentile across Yamaha models.
About 27% smaller than the Yamaha database average. Around the 32nd percentile across Yamaha models.
Yamaha database percentile rankings
Percentiles show where this motorcycle sits across the Yamaha specifications database. They are descriptive database rankings, not performance ratings.
125 cc — larger displacement than about 25% of Yamaha models.
105 kg — heavier than about 14% of Yamaha models, or lighter than about 86%.
9.5 L — larger than about 32% of Yamaha fuel tanks in this database.
Mechanical overview
Additional useful specifications
| Front tire size | 2.50-18 |
|---|---|
| Rear tire size | 2.75-18 |
| Bore/stroke ratio | 1.00:1 (Square) |
Model information
| Year released | 1970 |
|---|
Engine specifications
| Engine type | Twin, two-stroke |
|---|---|
| Displacement | 125 cc (7.63 cu in) |
| Bore × stroke | 43.0 x 43 mm (1.7 x 1.7 inches) |
| Compression ratio | 7.0:1 |
| Cooling system | Air |
| Fuel control | Port control |
Transmission and drivetrain
| Gearbox | 5-speed |
|---|---|
| Final drive | Chain (final drive) |
Brakes, wheels and tires
| Front brakes | Expanding brake |
|---|---|
| Rear brakes | Expanding brake |
| Front tire | 2.50-18 |
| Rear tire | 2.75-18 |
Dimensions and weight
| Wet weight | 105 kg (231.5 lb) |
|---|
Fuel and emissions
| Fuel capacity | 9.50 L (2.51 US gal) |
|---|
Performance
| Top speed | 110.0 km/h (68.4 mph) |
|---|
Disclaimer: Specifications may vary by market, trim, production date and optional equipment, and scraped or historical data can contain errors. Comparison and percentile values are calculated from Yamaha models in this specifications database. Always double-check important specifications against the motorcycle owner’s/service manual and official Yamaha information before relying on them. Visit the official Yamaha website.