Yamaha YS125 Specs (Top Speed | Horsepower | Weight)

The Yamaha YS125 motorcycle specifications include a 125 cc (7.63 cu in) engine, power of 10.5 hp (7.6 kW) @ 7,500 rpm, a 5-speed gearbox, and a listed weight of 129 kg (284.4 lb).

Key specifications

2018-2021Model years
125 ccDisplacement
10.5 hpPower
10.8 Nm @ 6,000 rpmTorque
129 kgWet weight
795 mmSeat height
14 LFuel tank
1,320 mmWheelbase
Model years covered
2018201920202021
Year-specific specification changes

The 2018 model is treated as the standard specification. Only later model years with a different supplied value are shown below.

Bore × stroke
2020202154.4 x 57.9 mm (2.1 x 2.3 inches)
Engine type
20202021Single cylinder, two-stroke
Front brakes
20202021Single disc. Hydraulic.
Front suspension
20202021Telescopic fork
Fuel system
2020Carburettor
Gearbox
202020216-speed
Rear brakes
20202021Expanding brake (drum brake). Hydraulic.
Rear suspension
20202021Swing arm
Clutch
20202021O-ring chain
Cooling system
2020Liquid
Ignition
2020CDI
Rake
2020202126.8°
Rear wheel travel
20202021112 mm (4.4 inches)
Trail
20202021117 mm (4.6 inches)

How the Yamaha YS125 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.

Engine power10.5 hp
Low 2.8 hpAverage 53.3 hpHigh 171.2 hp

About 80% lower than the Yamaha database average. Around the 18th percentile across Yamaha models.

Displacement125 cc
Low 49 ccAverage 550 ccHigh 1,852 cc

About 77% lower than the Yamaha database average. Around the 25th percentile across Yamaha models.

Wet weight129 kg
Low 72.1 kgAverage 186.3 kgHigh 348.7 kg

About 31% lighter than the Yamaha database average. Around the 26th percentile across Yamaha models.

Seat height795 mm
Low 635 mmAverage 793 mmHigh 989 mm

Very close to the Yamaha database average. Around the 55th percentile across Yamaha models.

Fuel capacity14 L
Low 4 LAverage 13 LHigh 24 L

About 7% larger than the Yamaha database average. Around the 57th percentile across Yamaha models.

This model Yamaha database average

Mechanical overview

Engine layout snapshot

Single cylinder, four-stroke • 125 cc • Air cooled • 10.5 hp
Chassis snapshot

Wheelbase 1,320 mmSeat 795 mmClearance 150 mm
5-speed • Chain (final drive) • 2.75-18 front / 100/80-18 rear

Additional useful specifications

Front tire size 2.75-18
Rear tire size 100/80-18
Rear tire width 100 mm
Rear tire aspect ratio 80%
Rear rim diameter 18 in
Engine oil capacity 1.20 L (1.27 US qt)
Power-to-weight ratio 0.081 hp/kg
Power-to-weight 81.4 hp/tonne
Specific power 84.0 hp/L
Bore/stroke ratio 0.91:1 (Undersquare)

Engine specifications

Engine type Single cylinder, four-stroke
Displacement 125 cc (7.63 cu in)
Power 10.5 hp (7.6 kW) @ 7,500 rpm
Torque 10.8 Nm (1.1 kgf-m or 8.0 ft.lbs) @ 6,000 rpm
Bore × stroke 52.4 x 57.9 mm (2.1 x 2.3 inches)
Compression ratio 10.0:1
Valves per cylinder 2
Cooling system Air
Fuel system Injection
Fuel control Single Overhead Cams (SOHC)
Ignition TCI
Starter Electric
Lubrication Wet sump
Oil capacity 1.20 L (1.27 US qt)

Transmission and drivetrain

Gearbox 5-speed
Final drive Chain (final drive)
Clutch Wet, multiple-disc coil spring

Chassis and suspension

Frame Steel, diamond shaped
Front suspension Telescopic forks
Rear suspension Swingarm
Front wheel travel 120 mm (4.7 inches)
Rear wheel travel 105 mm (4.1 inches)
Rake 26.0°
Trail 90 mm (3.5 inches)

Brakes, wheels and tires

Front brakes Single disc
Rear brakes Expanding brake (drum brake)
Front tire 2.75-18
Rear tire 100/80-18

Dimensions and weight

Wet weight 129 kg (284.4 lb)
Seat height 795 mm (31.3 inches)
Overall length 2,005 mm (78.9 inches)
Overall width 735 mm (28.9 inches)
Overall height 1,050 mm (41.3 inches)
Wheelbase 1,320 mm (52.0 inches)
Ground clearance 150 mm (5.9 inches)

Fuel and emissions

Fuel capacity 14.00 L (3.70 US gal)

Other specifications

Color options White, red, black
Seat Dual seat and passenger grab rails

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.