Positioned in Tomos's scooter motorcycle lineup, the 1977 Tomos APN 4 utilizes a 48.8 cc (3 cu in) air-cooled single cylinder, two-stroke layout. In factory specification, peak output is rated at 3.5 HP (2.6 kW) at 6,200 rpm while maximum torque reaches 3.8 Nm (2.8 lb-ft) at 5,800 rpm, transferring power to the rear wheel through a 4-speed gearbox and chain final drive. Internal engine geometry specifies a bore and stroke of 38.0 x 43.0 mm (1.5 x 1.7 inches) with a 10.0:1 compression ratio.
On the scales, the APN 4 measures 67 kg (148 lbs) wet (curb). The 5-liter (1.3 US gal) fuel tank paired with a rated consumption of 2 L/100 km provides an estimated theoretical range of roughly 250 km (155 miles) between fill-ups, while factory top speed is listed at 55 km/h (34 mph).
Power Band Window
5,800–6,200 rpm
Theoretical Range
~250 km (155 mi)
Engine
Displacement48.8 ccm (2.98 cubic inches)
Engine TypeSingle cylinder, two-stroke
Power3.5 HP (2.6 kW)) @ 6200 RPM
Torque3.8 Nm (0.4 kgf-m or 2.8 ft.lbs) @ 5800 RPM
Compression10.0:1
Bore x Stroke38.0 x 43.0 mm (1.5 x 1.7 inches)
Fuel SystemCarburettor
Fuel ControlMembrane
CoolingAir
Transmission
Gearbox4-speed
Final DriveChain (final drive)
Performance
Top Speed55.0 km/h (34.2 mph)
Fuel Consumption2.00 litres/100 km (50.0 km/l or 117.61 mpg)
Greenhouse Gases46.4 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.
Fuel Capacity
Fuel capacity helps estimate touring range and how often you may need to stop.
Transmission
Transmission and final drive affect maintenance, smoothness and everyday usability.
