ENGINE SYSTEM AND SADDLE-TYPE VEHICLE

During start-up of an engine, a reverse rotation start-up operation of rotating a crankshaft in a forward direction is performed after rotation of the crankshaft in a reverse direction. In the operation, a fuel injection device injects fuel such that a fuel-air mixture is introduced into a combustion chamber from an intake passage through an intake port, at at least one of a time when the crankshaft is rotated in the reverse direction and a crank angle is in a start-up intake range and a time when the crankshaft is rotated in the forward direction and the crank angle is in the normal intake range, and an ignition device ignites the fuel-air mixture in the combustion chamber when the crank angle is in a start-up ignition range. An engine unit is controlled such that the operation is performed again, in a case in which a rotation state detected by a rotation state detector does not satisfy a predetermined start-up condition, when the crankshaft is rotated in the forward direction in the operation and before a piston reaches a first compression top dead center.