Decompression device and engine

An engine including a cylinder body in which a plurality of cylinders are formed, the engine comprising:

• an exhaust camshaft supported by a cylinder head;
• and
• a plurality of decompression devices attached to the exhaust camshaft, wherein each of the decompression devices includes:
• a decompression camshaft formed with a decompression cam that can protrude and be immersed with respect to a base circle of an exhaust cam of the exhaust camshaft;
• a decompression arm that moves in an opening direction due to centrifugal force accompanying rotation of the exhaust camshaft to protrude the decompression cam;
• a spring that moves the decompression arm in a closing direction by spring force resisting the centrifugal force to immerse the decompression cam;
• and
• a decompression holder for holding the decompression camshaft, the decompression arm, and the spring on an outer surface of the exhaust camshaft,
• in one of the decompression devices a base end of the decompression arm is connected to the decompression holder on a leading side in a rotation direction of the exhaust camshaft and a tip end of the decompression arm is connected to the decompression cam on a trailing side in the rotation direction, and in another one of the decompression devices the base end of the decompression arm is connected to the decompression holder on the trailing side in the rotation direction and the tip end of the decompression arm is connected to the decompression cam on the leading side in the rotation direction, so that the opening direction of the decompression arm of the one of the decompression devices is in a same direction as the rotation direction of the exhaust camshaft and the opening direction of the decompression arm of the another one of the decompression devices is in an opposite direction to the rotation direction of the exhaust camshaft depending on an attachment orientation of the decompression holders with respect to the exhaust camshaft.