HARLEY-DAVIDSON 74 – year 1930
Manufacturer: AMF Harley-Davidson Motor Co., Inc., Milwaukee, Wisconsin, USA
Harley-Davidson used solutions in its pre-war models, which soon made her famous all over the world: longitudinally located V-shaped two-cylinder engine with a lower valve timing, separated, manually controlled, transmission, front Harley” a fork with short wishbones and a wide saddle, sprung with a spring hidden in the rear, the seat tube of the frame.
Model 74 with 1930 Its design was based on the tried and tested liter model from the First World War. However, it had an increased cylinder diameter (with 84,1 mm do 86,9 mm) and the stroke of the piston (with 88,9 mm do 101,6 mm). New engine (constructed by the famous English engineer Harry Ricard) it had a low-valve timing and a removable cylinder head. The carburetor was from Schebler, and the ignition system was battery powered. The drive from the engine to the clutch was carried by a double-row chain, and a single-row chain from the gearbox to the rear wheel. The nine-disc clutch was pedal-operated. The three-speed gearbox was soon replaced with a four-speed reverse gearbox, facilitating driving and a sidecar. The single tubular frame had only the front wheel sprung by a custom fork with four coil springs. Both wheels were equipped with drum brakes. The steering wheel had a friction steering damper. Wide size balloon tires 27 x 4, big "saddle"” fuel tank with a capacity 12,75 liters (with 5,4 liter of reserve) and two headlights and an electric sound signal in front of the steering wheel completed the equipment of this interesting machine. The motorcycle was reaching speeds of the order 140 km/h.
W 1939 In the year, the engine capacity was increased again. By extending the piston stroke to 108 mm obtained 1281 cm3 (it was probably the largest capacity of a series motorcycle engine at that time).
Model 74, successfully sold also in Europe, it even survived the Second World War in production. Model 74 with 1951 He had an overhead valve 0HV with hydraulic tappets to regulate the valve clearance. Engine power increased to 36,8 kW (50 KM). It was produced until 1955 year.