| 摘要 |
<p>Breather mechanism (25) includes a breather passage (51) opening into a crankcase (35), a breather chamber 52) communicating with the crankcase via the breather passage, and a valve (53; 92) provided in the breather chamber and openable to allow blow-by gas to flow from the crankcase into the breather chamber once inner pressure of the crankcase exceeds a predetermined value. When the engine is placed in a laterally laid-down position, entry, into the breather chamber, of lubricating oil is prevented by the breather passage (51). When the engine is placed in a vertically upright position, an outlet end portion (58b) of the breather passage is located above an inlet end portion (59) of the breather passage.</p> |
