Raw Water Strainer Empty

[Harold Fahs]

I just returned from the first sailing trip since owning an 85 C30. After sailing on a port tack for some time I started the engine only to have it overheat. Since I have just rebuilt the whole cooling system, this was a suprise as it had been running at 160 degrees for hours previously. I checked the raw water filter and it was empty. After closing the thru-hull and removing the lid, I reopened the thru hull and it filled with water. I started the engine and it still stayed hot. After some time pulling hoses off and checking flow, I found that if I removed the hose from the top of the valve under the sink and depressing the valve it would let water flow through the exhaust. Since I was miles off shore and getting tired of playing these games every time I started the engine I finally by-passed the valve by runnig the hose off the heat exchanger direct to the connection in the exhaust pipe that goes to the muffler, and no more overheating. Does any one know if this will harm anything? What is the purpose of the "Y" valve under the sink? Any help would be appreciated.

 

[S. Hockey]

no water flow

First is your engine a m25? You have three connections to the "Y", one would be the inlet from the exchanger, one maybe to your exhaust, where does third hose go? On my m25xp, 1991, there is no "y" valve on the raw water line, You might have a "Y" on your glycol system to feed the hot water tank, but on the raw water side I cannot think of a reason. From the exchanger, the raw water goes directly to the exhaust so you are ok running it that way. Find out where all of the hoses go to from the "Y" valve and it might give you or us a clue as to what is happening. The "Y" valve might be defective and preventing raw water flow.Good luck.