Patent ID: 7077078

Claim:
An engine cooling structure for an engine including a cylinder, an exhaust muffler connected to the cylinder, and an engine cover covering the cylinder and the exhaust muffler, wherein: the engine cover defines together with the cylinder a space connected through a cooling air inlet to a cooling air supply device; the exhaust muffler has an exhaust gas discharge opening formed near a back end part of a side, which is opposite to a side facing the cylinder, of the exhaust muffler, the exhaust gas discharge opening being positioned at a height included in a vertical dimension of the cylinder; and a cooling air passage, through which a cooling air taken in the space defined by the engine cover and the cylinder through the cooling air inlet flows, is formed so as to cool the cylinder and the exhaust muffler, the cooling air passage including a main cooling passage for guiding part of the cooling air used for cooling the cylinder through a space around the exhaust muffler to a space around the exhaust gas discharge opening of the exhaust muffler, and a cooling air bypass passage for guiding part of the cooling air used for cooling the cylinder directly to the space around the exhaust gas discharge opening of the exhaust muffler.