Positioned in Fosti's naked motorcycle lineup, the 2020 Fosti F51 pairs a 149 cc (9.1 cu in) single cylinder, four-stroke architecture with road-focused gearing. In factory specification, peak output is rated at 12.1 HP (8.8 kW) at 9,000 rpm while maximum torque reaches 9 Nm (6.6 lb-ft) at 7,500 rpm. With a specific output of 81.2 HP per liter and a 1,500 rpm working window between peak torque (7,500 rpm) and peak power (9,000 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 F51 measures 128 kg (282 lbs) wet (curb), translating to a power-to-weight ratio of 0.09 HP/kg (10.58 kg per horsepower). Rider ergonomics and chassis geometry center around a 1,180 mm (46.5 in) wheelbase engineered for quick, flickable steering geometry. The 15-liter (4 US gal) fuel tank paired with a rated consumption of 2.2 L/100 km provides an estimated theoretical range of roughly 682 km (424 miles) between fill-ups, while factory top speed is listed at 90 km/h (56 mph).
Within MotoLibrary's Fosti archive, this model family spans 2 indexed model years from 2020 to 2021, allowing buyers to track year-over-year changes in emissions tuning, weight and equipment.
Specific Output
81.2 HP/L
Power-to-Weight
0.09 HP/kg (10.58 kg/HP)
Power Band Window
7,500–9,000 rpm
Theoretical Range
~682 km (424 mi)
Engine
Displacement149.0 ccm (9.09 cubic inches)
Engine TypeSingle cylinder, four-stroke
Power12.1 HP (8.8 kW)) @ 9000 RPM
Torque9.0 Nm (0.9 kgf-m or 6.6 ft.lbs) @ 7500 RPM
Performance
Top Speed90.0 km/h (55.9 mph)
Fuel Consumption2.20 litres/100 km (45.5 km/l or 106.92 mpg)
Greenhouse Gases51.0 CO2 g/km. (CO2 - Carbon dioxide emission)
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.
Weight
Compare weight carefully because it affects low-speed handling, parking and confidence.
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.
