A four-stroke internal combustion engine with at least two inlet valves and an inlet flow path with at least two inlet ports per cylinder which branch off from a common inlet pipe and are guided separately up to the inlet valves and of which at least one inlet port is designed as a charge loading port and at least one inlet port as a volumetric port, with a throttle device for volumetric control being provided in the inlet flow path and the inlet flow path is connected with a fuel supply device. In order to achieve in the simplest possible way an improvement of the exhaust gas quality at low fuel consumption, the fuel supply device is formed by a joint carburetor for both inlet ports, with preferably the carburetor being arranged in the zone of the branching of the inlet ports from the inlet pipe.