ENGINE UNIT AND SADDLED VEHICLE

A desired amount of fuel vapor is introduced to a combustion chamber. A communication passage member 163 through which fuel vapor is introduced from a canister 161 into an intake passage member 110 is provided. A solenoid valve 170 is provided to the communication passage member 163. The solenoid valve 170 is provided so that the capacity of a part a communication passage 163a in the communication passage member 163, the part extending between the downstream intake passage 110x and the valve, is smaller than a half of the displacement of an engine 130. In a downstream intake passage portion 110d, pressure varies in a pressure-variation manner such that: a larger depression having a larger difference from atmospheric pressure and a smaller depression having a smaller difference from atmospheric pressure are created in each four-stroke cycle; and the creation of the larger and smaller depressions is repeated on a four-stroke basis. The solenoid valve 170 is controlled in association with the four-stroke-basis pressure-variation manner.