Positioned in Yamaha's sport motorcycle lineup, the 2021 Yamaha YZF-R125 relies on a 124.7 cc (7.6 cu in) liquid-cooled single cylinder, four-stroke powerplant. In factory specification, peak output is rated at 15 HP (10.9 kW) at 9,000 rpm while maximum torque reaches 11.5 Nm (8.5 lb-ft) at 8,000 rpm, transferring power to the rear wheel through a 6-speed gearbox and chain final drive. With a specific output of 120.3 HP per liter and a 1,000 rpm working window between peak torque (8,000 rpm) and peak power (9,000 rpm), the engine character is reflecting a performance-oriented street tune that balances strong mid-range pull with an energetic top-end rush.
On the scales, the YZF-R125 measures 144 kg (317 lbs) wet (curb), translating to a power-to-weight ratio of 0.1 HP/kg (9.6 kg per horsepower). Rider ergonomics and chassis geometry center around a 825 mm (32.5 in) seat height — resulting in a taller command-style riding posture suited to medium-to-tall inseams, combined with a 1,355 mm (53.3 in) wheelbase engineered for quick, flickable steering geometry. The 11.5-liter (3 US gal) fuel tank paired with a rated consumption of 2.13 L/100 km provides an estimated theoretical range of roughly 540 km (336 miles) between fill-ups.
Within MotoLibrary's Yamaha archive, this model family spans 12 indexed model years from 2008 to 2026, allowing buyers to track year-over-year changes in emissions tuning, weight and equipment.
Specific Output
120.3 HP/L
Power-to-Weight
0.1 HP/kg (9.6 kg/HP)
Power Band Window
8,000–9,000 rpm
Theoretical Range
~540 km (336 mi)
Engine
Displacement124.7 ccm (7.61 cubic inches)
Engine TypeSingle cylinder, four-stroke
Power15.0 HP (10.9 kW)) @ 9000 RPM
Torque11.5 Nm (1.2 kgf-m or 8.5 ft.lbs) @ 8000 RPM
Compression11.2:1
Bore x Stroke52.0 x 58.6 mm (2.0 x 2.3 inches)
Valves/Cylinder4
Fuel SystemInjection. EFI
Fuel ControlSingle Overhead Cams (SOHC)
IgnitionTCI
LubricationWet sump
CoolingLiquid
Transmission
Gearbox6-speed
Final DriveChain (final drive)
ClutchAssist and Slipper clutch
DrivelineConstant Mesh
Performance
Fuel Consumption2.13 litres/100 km (46.9 km/l or 110.43 mpg)
Greenhouse Gases49.4 CO2 g/km. (CO2 - Carbon dioxide emission)
Emission DetailsEuro 5
Chassis
Frame TypeCompact deltabox
Rake25.0°
Trail89 mm (3.5 inches)
Front SuspensionUpside-down telescopic fork, Ø 41 mm
Front Travel130 mm (5.1 inches)
Rear SuspensionLinked monoshock with spring preload adjustment
Rear Travel114 mm (4.5 inches)
Wheelbase1355 mm (53.3 inches)
Ground Clearance155 mm (6.1 inches)
Wheels & Brakes
Front Tyre100/80-17
Rear Tyre140/70-17
Front BrakesSingle disc
Front Brake Ø292 mm (11.5 inches)
Rear BrakesSingle disc
Rear Brake Ø230 mm (9.1 inches)
Dimensions & Weight
Weight incl.144.0 kg (317.5 pounds)
Seat Height825 mm (32.5 inches) If adjustable, lowest setting.
Use this page to compare this motorcycle by its real specifications, not only by model name. Focus on the details that affect fit, comfort, handling, range and ownership.
Power
Compare engine output with similar motorcycles if acceleration, highway use or two-up riding matters.
Torque
Torque is useful for judging real-world pull, especially for touring, commuting and loaded riding.
Seat Height
Check the seat height against your inseam and riding posture before choosing a motorcycle.
Fuel Capacity
Fuel capacity helps estimate touring range and how often you may need to stop.
Brakes
Brake setup is worth comparing if you ride in traffic, mountains or with a passenger.
Suspension
Suspension details can matter for comfort, road feel and long-distance riding.
Transmission
Transmission and final drive affect maintenance, smoothness and everyday usability.
