To provide an engine which has improved responsiveness to and accuracy of fuel control and to provide an engine work machine mounted with the engine.

An engine 4 is provided with a carburetor 13 which has: a fuel chamber 31 storing fuel supplied from a fuel tank 16; and an intake air passage 36 where the fuel supplied from the fuel chamber 31 is mixed with air. The engine 4 also has an electric pump 22 which is connected to the fuel chamber 31 and controls an amount of the fuel to be supplied from the fuel chamber 31 to the intake air passage 36 by changing pressure of the fuel chamber 31.