In a snowmobile, a four-cycle engine is mounted in such a manner that its crankshaft is arranged along the body width direction and the central axis of a cylinder(s) is tilted rearward by angle .alpha. with respect to the vertical direction of the body, forming a rear tilted engine. At least part of the engine intake system including an air cleaner box and throttle body, connected to the intake port(s) of the engine is accommodated in the space inside the topmost projected portion of the engine hood. Exhaust is led out to the muffler located in front of the cylinder(s) by the exhaust system connected to the exhaust port(s) at the front of the cylinder head. Further, the intake passage is arranged between the engine body and the steering post.