Internal combustion engine for saddle-riding vehicle

An internal combustion engine for a saddle-riding vehicle, wherein the engine is mounted on the saddle-riding vehicle, the internal combustion engine comprising:

• a cylinder head having a combustion chamber formed therein;
• a cylinder head cover covering the cylinder head;
• a fuel injection valve having a distal end directed to the combustion chamber;
• a valve train cam shaft rotatably supported in the cylinder head and having thereon a cam integrally rotatable with the cam shaft;
• a fuel pump mounting member fixed to the cylinder head in a state where the fuel pump mounting member covers at least a portion of the cam shaft;
• a fuel pump for feeding fuel by an action of the cam, the fuel pump being fixedly mounted on the fuel pump mounting member;
• and
• a downstream side fuel pipe for supplying fuel from the fuel pump to the fuel injection valve, the downstream side fuel pipe having a flexibility.