A four cycle power personal watercraft having an improved crankcase ventilating and induction system. The crankcase ventilating system ensures that the crankcase gases will be passed to the combustion chambers to eliminate unburned hydrocarbons from escaping to the atmosphere. However, the system is also designed so as to preclude separated lubricant from passing into the induction system and also to prevent water from entering the engine through the induction system or the ventilating system.