Moto Rumi
An Italian Masterpiece
Moto Rumi
In 1960, Harley-Davidson acquired 50% of the Aermacchi factory and assumed complete control in 1974. Harley-Davidson purchased Aermacchi in 1961, to produce lightweight motorcycles for the American market, in an attempt to capture a piece of the youth market back.
In 1965, Harley-Davidson brought a smaller two-stroke Aermacchi onto the market, the Zeffiretto. The name "Zeffiretto" was used for the Italian market. This 48cc machine came as a moped, the 48NP (P for pedals) and without pedals, a no-ped, hence 48N with no P. The engine is 38x42mm, plain piston-port, CR 8.5:1, with 3 speeds actuated by a hand shift. The 48NP was built until 1965, whilst the 48N continued until 1972.
In the United States Aermacchi sold these motorcycles as the "Harley-Davidson M 50 and M 65". The Zeffiretto / M 50 and M 65s were virtually unmarketable in Europe and in America, despite large advertising campaigns. In total only 200 examples of this rare Aermacchi Zeffiretto Sport 48 S (M50S) were built.
Specifications
Engine: Single cylinder, 2-stroke
Starter: Kick-starter
Bore & stroke: 38.8 x 42 mm
Compression ratio: 7.8:1
Engine Capacity: 49.6cc (3.03 cubic inches)
Maximum power: 1.5 h.p. @ 4,500 rpm
Valves per cylinder: 2
Ignition type: Dynamo - 6 volts - 18 watt
Carburettor: Dell'Orto SHA
Lubrication: Wet sump forced circulation with mechanical gear pump
Transmission: Gear primary, chain final
Clutch: Cable operated with multiple wet disk
Gearbox: 3-speed, gear shift
Throttle: Cable operated
Cooling system: Air cooled
Frame type: Tubular pressed steel and backbone frame
Front Suspension: Telescopic
Rear Suspension: Mono shock, Swingarm
Front Brake: Drum
Rear Brake: Drum
Front tyre: 2.00 x 18 in.
Rear tyre: 2.00 x 18 in.
Wheelbase: 44.1 inches
Seat: Duck-tail dual seat
Fuel tank capacity: 6 litres
Top speed: 45 km/h
Weight: 52.5 Kg
Price in 1966: US$275 plus tax
Bibliography: Legend Bike Magazine: Volume 8. no. 80, May 1999, pages 42-43
Source: Hessink's NL
After the Brezza (the first 2-stroke) a smaller 2-stroke followed. It's a 2-stroke engine of 47,61cc: a moped. The P in 48 NP stands for pedals. The 2-stroke engine is actually very simple: a piston-controlled in/exhaust-system with two overflow ports and a slightly curved piston; a bore and stroke of 38 x 42 giving 48.61cc, with a compression-ratio of 8.5:1 [1+2]. The front and rear suspension were hydraulic and the moped had a 3-gear hand-shifted.
The colours were light-green or grey and according to sources in Italy only two pedal equipped moped models were manufactured. The production of this model ended in 1965, the 48N ended in 1972. The 48N was not a success in Europe, only 967 were manufactured. The frame number of the NP-model starts with 300001, the 48N starts with 4000001.
This page is derived from an archive of 2stroke-nl
If you have a query about Aermacchi motorcycles please contact us
