Water-cooled internal combustion engine having radiator

A water-cooled internal combustion engine, comprising:

• a cylinder block being provided with a cylinder block water jacket;
• a cylinder head being provided with a cylinder head water jacket;
• and
• a cooling device provided with a water pump for pressure-feeding cooling water to the water jackets;
• a radiator operatively connected to said cooling device through which the cooling water of the water jackets circulates, said radiator being disposed to be separate from the cylinder block in a prescribed direction;
• and
• a chain chamber for accommodating a transmission mechanism for a valve system disposed extending, along a cylinder axis, from the cylinder block to the cylinder head and being provided in an end portion toward the radiator in the prescribed direction of the cylinder block, the water-cooled internal combustion engine comprising:
• a cooling water outlet portion open to the cylinder head water jacket provided in a portion, included in the end portion, of the cylinder head, the cooling water outlet portion being connected with an inlet pipe for leading the cooling water flowing out of the cylinder block water jacket into the cylinder head water jacket to the radiator;
• and
• the upper end of the portion of the water jacket overlapping the chain chamber in the lateral direction and the outlet portion to be connected to an outlet pipe positioned closer to the radiator than the chain chamber.