Patent ID: 8893609

Claim:
An engine body comprising: a crankcase having a crank chamber formed therein and a breather passage outside of the crank chamber for permitting fluid communication between the crank chamber and an area outside of the engine body; a breather apparatus comprising a one-way valve interposed between the crank chamber and the breather passage, wherein the one-way valve is configured to allow a one-way gas flow therethrough from the crank chamber to the breather passage, wherein the one-way valve is a pressure-responsive valve which is operatively attached to a side wall of the engine body proximate a cylinder sleeve thereof, wherein a timing chamber, which houses a timing power transmission device therein, extends between the crankcase and a cylinder block of the engine body adjacent to the cylinder sleeve, and wherein the side wall on which the one-way valve is mounted is a side wall of the crankcase interposed between the timing chamber and the crank chamber, and wherein the timing chamber functions as a part of the breather passage.