Electromagnetically operated pump

An electromagnetically operated pump, to feed two-stroke internal-combustion engines with precise and controlled amounts of oil, comprises in a casing (1): a cylinder (2); a piston element (3) with a through pipe (4), axially movable in said cylinder (2); an electromagnetic coil (10) external to the cylinder (2), to control the movements of the piston element (3) against the action of spring means (11); a pumping and metering chamber (7) for the oil to be fed, at one end (9) of the cylinder (2); and valve means (12, 13) housed in said casing (1) close to said end (9), one of said means (12) cooperating with said piston element (3). According to the invention, two opposite abutments (14, 15) are formed on the piston element (3), said abutments (14, 15) cooperating with corresponding abutments (16, 17) of an element apt to stop the cylinder (2) into the casing (1). In said pump, the stroke (C) of the piston element (3) into the cylinder (2) is limited exclusively by the cooperation between said abutments (14, 15 and 16, 17) which thereby determine the metering of the oil to be fed.