The Yamaha YB-1 Four motorcycle specifications include a 49 cc (2.99 cu in) engine, power of 4.1 hp (3.0 kW) @ 7,500 rpm, a 4-speed gearbox, and a listed weight of 83 kg (183 lb).
Key specifications
How the Yamaha YB-1 Four 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 92% lower than the Yamaha database average. Around the 8th percentile across Yamaha models.
About 91% lower than the Yamaha database average. Around the 5th percentile across Yamaha models.
About 6% lower than the Yamaha database average. Around the 24th percentile across Yamaha models.
About 45% smaller than the Yamaha database average. Around the 21st 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.
4.1 hp — more powerful than about 8% of Yamaha models with power data.
49 cc — larger displacement than about 5% of Yamaha models.
745 mm — taller than about 24% of Yamaha models.
7.2 L — larger than about 21% of Yamaha fuel tanks in this database.
Dimensions compared with Yamaha average
Each measurement is compared with the average value across Yamaha models where that dimension is available.
1,785
2,082
14% below average.
655
823
20% below average.
960
1,172
18% below average.
1,190
1,416
16% below average.
745
793
6% below average.
130
181
28% below average.
Mechanical overview
Additional useful specifications
| Power-to-weight ratio | 0.049 hp/kg |
|---|---|
| Power-to-weight | 49.4 hp/tonne |
| Specific power | 83.7 hp/L |
| Bore/stroke ratio | 0.74:1 (Undersquare) |
Model information
| Year released | 2002 |
|---|---|
| Category | Classic |
Engine specifications
| Engine type | Single cylinder, four-stroke |
|---|---|
| Displacement | 49 cc (2.99 cu in) |
| Power | 4.1 hp (3.0 kW) @ 7,500 rpm |
| Torque | 4.0 Nm (0.4 kgf-m or 3.0 ft.lbs) @ 6,000 rpm |
| Bore × stroke | 36.0 x 48.6 mm (1.4 x 1.9 inches) |
| Compression ratio | 9.5:1 |
| Valves per cylinder | 2 |
| Cooling system | Air |
| Fuel system | Carburettor |
| Fuel control | Single Overhead Cams (SOHC) |
Transmission and drivetrain
| Gearbox | 4-speed |
|---|---|
| Final drive | Chain (final drive) |
Brakes, wheels and tires
| Front brakes | Expanding brake |
|---|---|
| Rear brakes | Expanding brake |
Dimensions and weight
| Dry weight | 83 kg (183 lb) |
|---|---|
| Seat height | 745 mm (29.3 inches) |
| Overall length | 1,785 mm (70.3 inches) |
| Overall width | 655 mm (25.8 inches) |
| Overall height | 960 mm (37.8 inches) |
| Wheelbase | 1,190 mm (46.9 inches) |
| Ground clearance | 130 mm (5.1 inches) |
Fuel and emissions
| Fuel capacity | 7.20 L (1.90 US gal) |
|---|
Performance
| Power/weight ratio | 0.0494 hp/kg |
|---|
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.