The Aprilia SR50 is a scooter built by

Aprilia Aprilia is an Italian motorcycle and Scooter (motorcycle), scooter manufacturer in Noale, Italy, founded by Alberto Beggio. History Early days Aprilia, named after the Pre-war automobile, pre-war Lancia Aprilia, was founded after the Seco ...

History

Introduced in 1992, more than 800,000 units have been sold, bucking the trend for less use of

two-stroke engines A two-stroke (or two-stroke cycle) engine is a type of internal combustion engine that completes a Thermodynamic power cycle, power cycle with two strokes of the piston, one up and one down, in one revolution of the crankshaft in contrast to a f ...

. Aprilia claims several firsts for the SR50 in the scooter market, including 13 inch wheels, liquid cooling, double disc braking, and a direct injection engine. The performance-oriented suspension, tires, and engine are consistent with its styling. Colours and graphics vary by country. The digital instrument panel gives readings for speed, clock, odometer, trip counter, fuel level, coolant temperature and battery voltage. The SR50 has used a variety of engines, sourced from

Morini The Morini (Gaulish language, Gaulish: 'sea folk, sailors') were a Belgae, Belgic coastal tribe dwelling in the modern Pas-de-Calais, Pas de Calais region, around present-day Boulogne-sur-Mer, during the La Tène culture, Iron Age and the Roman ...

, Piaggio and

Minarelli Motori Minarelli is an Italian motorcycle engine manufacturer. It is part of the Fantic Motor group. History Motori Minarelli was founded in Bologna in 1951 as a motorcycle manufacturer. In 1954 it also began to build mopeds. Two years later Mi ...

. It conforms to EURO 3 emission standards. The DiTech model used an injection engine, with technology from Orbital. The current model uses a

Dell'Orto Dell'Orto is an Italian company, headquartered in Cabiate, specialized in the construction of carburetors and electronic injection systems. The company was founded in 1933 as "Società anonima Gaetano Dell'Orto e figli" (Gaetano Dell’Orto and ...

carburetor. The powerful engines allow reaching very high speeds for a scooter, the SR50 can reach 90 km/h in its standard configuration after being derestricted.

DITECH two-stroke engine

The SR50 DITECH uses the Synerject gasoline direct injection (GDI) system developed jointly by the

Orbital Corporation Orbital Corporation Limited (), formerly Orbital Engine Corporation Limited pioneered by Ralph Sarich, is an Australian company based in Balcatta, Western Australia, that aims to provide clean engine technologies and alternative fuel systems ...

and

Siemens Siemens AG ( ) is a German multinational technology conglomerate. It is focused on industrial automation, building automation, rail transport and health technology. Siemens is the largest engineering company in Europe, and holds the positi ...

AG. The system uses a crank-driven air compressor to deliver air to the cylinder head at a pressure of , thereby avoiding the use of carburation; the cylinder walls are not wet with gasoline, only with lubricating oil. After the port is closed and the air is compressed by the piston, gasoline is injected by an atomizer like a spray nozzle mixed with and propelled by the highly compressed air, into the main combustion chamber where, after the injection port closes, and the piston is still rising, it is ignited in the compressed main charge of air. The use of direct injection and stratified charge allows the DITECH engine to meet Euro 2 standards. A small amount of crankcase oil is present in the compressed air used to atomize the fuel, but that was found to present no problems in the production of large numbers of the scooter. A problem was found with varying input humidity producing varying condensation water in the compressor system, and Aprilia deployed an oem retrofit solenoid valve to be installed near the injector which would drain the system of accumulated water each time the engine was switched off. Users complained that without this retrofit, the spark plug would accumulate carbon, and commented that with the retrofit, operation was trouble free. 2007 Aprilia SR50R Scooters

References

External links

Official Website

aprilia.com

apriliaforum.com
{{Aprilia motorcycles Motor scooters SR50 Motorcycles introduced in 1992 Two-stroke motorcycles Single-cylinder_motorcycles