Built around Yamaha's cross - motocross motorcycle platform, the 2002 Yamaha TT-R 90 features a 89 cc (5.4 cu in) liquid-cooled single cylinder, four-stroke configuration. In factory specification, peak output is rated at 5.6 HP (4.1 kW) at 7,000 rpm while maximum torque reaches 6.1 Nm (4.5 lb-ft) at 4,000 rpm. With a specific output of 62.9 HP per liter and a 3,000 rpm working window between peak torque (4,000 rpm) and peak power (7,000 rpm), the engine character is indicating a tractable, stress-free state of tune focused on everyday usability and broad torque delivery.
On the scales, the TT-R 90 measures 60 kg (132 lbs) dry, translating to a power-to-weight ratio of 0.09 HP/kg (10.71 kg per horsepower). Rider ergonomics and chassis geometry center around a 625 mm (24.6 in) seat height — giving shorter riders and urban commuters confident flat-foot reach at traffic stops, combined with a 1,040 mm (40.9 in) wheelbase engineered for quick, flickable steering geometry.
Within MotoLibrary's Yamaha archive, this model family spans 2 indexed model years from 2002 to 2007, allowing buyers to track year-over-year changes in emissions tuning, weight and equipment.
Specific Output
62.9 HP/L
Power-to-Weight
0.09 HP/kg (10.71 kg/HP)
Power Band Window
4,000–7,000 rpm
Standover Height
625 mm (24.6 in)
Engine
Displacement89.0 ccm (5.43 cubic inches)
Engine TypeSingle cylinder, four-stroke
Engine DetailsSingle cylinder, four-stroke
Power5.6 HP (4.1 kW)) @ 7000 RPM
Torque6.1 Nm (0.6 kgf-m or 4.5 ft.lbs) @ 4000 RPM
Compression8.5:1
Bore x Stroke47.0 x 51.8 mm (1.9 x 2.0 inches)
Fuel ControlSingle Overhead Cams (SOHC)
CoolingLiquid
Chassis
Front Travel110 mm (4.3 inches)
Rear Travel95 mm (3.7 inches)
Wheelbase1040 mm (40.9 inches)
Ground Clearance157 mm (6.2 inches)
Wheels & Brakes
Front BrakesExpanding brake
Rear BrakesExpanding brake
Dimensions & Weight
Dry Weight60.0 kg (132.3 pounds)
Power/Weight0.0933 HP/kg
Seat Height625 mm (24.6 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.
Weight
Compare weight carefully because it affects low-speed handling, parking and confidence.
Brakes
Brake setup is worth comparing if you ride in traffic, mountains or with a passenger.
