Re: 5.0 mercruiser, quick question
tcross,
In your picture, just to the right of the blue portion of the pump, is a blue colored cap. Just above the blue colored cap is a brass release valve with a ring on the end of the release valve. The white and green tubing will run down to the drains which are mounted on the sides of the engine.
What you have is a single point drain on your engine. Remove the blue colored cap and connect the hand pump. Pump it a few times and you should see a couple of little indicators pop up near the release valve and water will be expelled into the bilge from the single point drains the sides of the engine. Once the water is expelled, pull the ring on the release valve, the little indicators will retract and the single point drains should close.
One word of caution......I would advise NOT to use the single point drain with the boat setting in the water. A boating buddy of mine routinely did so on his 496 MAG engine. One Monday morning, he got a call from the marina as the boat had sunk while tied up to the dock. The cause....one of the single point drains mounted on the engine was located at or below the waterline. The single point drain did NOT fully close and thus water enter the boat through the partially open single point drain. The bilge pumps drained the batteries and the boat sank tied up at the dock.
On the 496 MAG engine, the single point drain on the starboard side of the engine is located and connected to the hoses between the outdrive and the raw water pump mounted on the front of the engine. Thus if the single point drain is below the water line and does not fully close.....water will enter the boat. The drain on the port side is located above the water line and should not cause any problems if it does not fully close. The drain valve locations on other size engines could be located differently from those on the 496 MAG engine. Just be aware that the potential exists to create a bigger problem if the drain valve doesn't fully close and the boat is setting in the water.
