At the heart of the 2011 Yamaha YFM90 atv motorcycle, Yamaha features a 88 cc (5.4 cu in) air-cooled single cylinder, four-stroke configuration. Internal engine geometry specifies a bore and stroke of 47.0 x 51.0 mm (1.9 x 2.0 inches) with a 10.2:1 compression ratio.
On the scales, the YFM90 measures 120 kg (265 lbs) wet (curb). Rider ergonomics and chassis geometry center around a 654 mm (25.7 in) seat height — giving shorter riders and urban commuters confident flat-foot reach at traffic stops, combined with a 1,010 mm (39.8 in) wheelbase engineered for quick, flickable steering geometry. The 4.8-liter (1.3 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 2009 to 2019, allowing buyers to track year-over-year changes in emissions tuning, weight and equipment.
Standover Height
654 mm (25.7 in)
Engine
Displacement88.0 ccm (5.37 cubic inches)
Engine TypeSingle cylinder, four-stroke
Engine DetailsSingle cylinder, four-stroke
Compression10.2:1
Bore x Stroke47.0 x 51.0 mm (1.9 x 2.0 inches)
Valves/Cylinder2
Fuel SystemCarburettor
Fuel ControlSingle Overhead Cams (SOHC)
IgnitionDC-CDI
LubricationWet sump
CoolingAir
Transmission
GearboxAutomatic
Final DriveChain (final drive)
Driveline2WD
Chassis
Front SuspensionIndependent double wishbone, 78 mm stroke
Rear SuspensionSwingarm, 83 mm stroke
Wheelbase1010 mm (39.8 inches)
Ground Clearance100 mm (3.9 inches)
Wheels & Brakes
Front Tyre18/7-8
Rear Tyre18/9-8
Front BrakesExpanding brake (drum brake)
Rear BrakesSingle disc
Dimensions & Weight
Weight incl.120.0 kg (264.6 pounds)
Seat Height654 mm (25.7 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.
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.
