Four stroke internal combustion engine with at least two intake valves per cylinder

The four-stroke engine has at least two inlet ports (4,5) leading to the inlet valves (2,3), the second port having a throttling device operated in dependence upon engine load. The throttling device (15), in the form of a flap or slide, to produce a defined minimum flow rate has a leakage opening. Preferably the throttling device is located in the region of a defined opening (12) in the partitioning wall (10) between the two inlet ports. The throttling device may be located hydraulically downstream of the mouth (11a) of the fuel injection valve (11).