Engineered by Yamaha for the scooter motorcycle segment, the 2018 Yamaha Aerox 4 pairs a 49 cc (3 cu in) liquid-cooled single cylinder, four-stroke architecture with road-focused gearing. In factory specification, peak output is rated at 3 HP (2.2 kW) at 7,240 rpm while maximum torque reaches 3.3 Nm (2.4 lb-ft) at 4,500 rpm, transferring power to the rear wheel through a automatic gearbox and belt final drive. Internal engine geometry specifies a bore and stroke of 38.0 x 43.5 mm (1.5 x 1.7 inches) with a 12.0:1 compression ratio.
On the scales, the Aerox 4 measures 97 kg (214 lbs) wet (curb). Rider ergonomics and chassis geometry center around a 817 mm (32.2 in) seat height — resulting in a taller command-style riding posture suited to medium-to-tall inseams, combined with a 1,275 mm (50.2 in) wheelbase engineered for quick, flickable steering geometry. The 6-liter (1.6 US gal) fuel tank supports practical everyday commuting and weekend road stints.
Within MotoLibrary's Yamaha archive, this model family spans 5 indexed model years from 2014 to 2021, allowing buyers to track year-over-year changes in emissions tuning, weight and equipment.
Power Band Window
4,500–7,240 rpm
Standover Height
817 mm (32.2 in)
Engine
Displacement49.0 ccm (2.99 cubic inches)
Engine TypeSingle cylinder, four-stroke
Power3.0 HP (2.2 kW)) @ 7240 RPM
Torque3.3 Nm (0.3 kgf-m or 2.4 ft.lbs) @ 4500 RPM
Compression12.0:1
Bore x Stroke38.0 x 43.5 mm (1.5 x 1.7 inches)
Fuel SystemInjection
Fuel ControlSingle Overhead Cams (SOHC)
IgnitionTCI
LubricationWet sump
CoolingLiquid
Transmission
GearboxAutomatic
Final DriveBelt (final drive)
DrivelineV-Belt Automatic
Chassis
Frame TypeSteel, tubular
Front SuspensionTelescopic fork
Front Travel80 mm (3.1 inches)
Rear SuspensionHydraulic unit swing
Rear Travel60 mm (2.4 inches)
Wheelbase1275 mm (50.2 inches)
Ground Clearance118 mm (4.6 inches)
Wheels & Brakes
Front Tyre120/70-13
Rear Tyre130/60-13
Front BrakesSingle disc
Front Brake Ø190 mm (7.5 inches)
Rear BrakesSingle disc
Rear Brake Ø190 mm (7.5 inches)
Wheels5-spoke cast aluminium
Dimensions & Weight
Weight incl.97.0 kg (213.8 pounds)
Seat Height817 mm (32.2 inches) If adjustable, lowest setting.
Overall Height1154 mm (45.4 inches)
Overall Length1876 mm (73.9 inches)
Overall Width706 mm (27.8 inches)
Fuel Capacity6.00 litres (1.59 US gallons)
Other
StarterElectric & kick
Color OptionsMatte grey, blue
InstrumentsLCD instruments
Carrying CapacityUnder-seat helmet storage for a full-face helmet.
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.
