Mid cam engine

A drive train (11) for an overhead valve engine (10), including a cam gear (106) driven by the crankshaft (12), the cam gear supported for rotation in the cylinder block (32) externally of the cylinder head (36) and having a cam lobe (214) mounted thereon for actuating a pair of rocker arms (162a, 162b) mounted for rotation in the cylinder head, which in turn actuates intake and exhaust valves (232a, 232b) in the cylinder head. A first lubrication passageway (152) is provided in the crankcase (18) of the engine to communicate oil, pumped from the oil sump (24) by a combination oil pump and governor assembly (120) driven from the crankshaft, to the upper crankshaft bearing (14). A second lubrication passageway (160) is provided in the crankshaft and communicates oil from the upper crankshaft bearing to the coupling between the crankshaft and the connecting rod (98). An air cleaner body (188) includes an integrally formed fitting (194) extending therefrom, which fits within an opening (180) in the breather cover (178) to directly communicate the breather chamber (170) with the air cleaner (58), wherein the air cleaner body may be mounted to the cylinder block in an easy, one-step operation in which the fitting is inserted into the breather cover opening and the air cleaner body is fastened directly to a mounting flange (206) of the carburetor (54).