Waterlock

[Don McCoy]

I recently discovered that one of the hose clamps (only one on each end) was leaking at one end of my "muffler". As I was reinstalling it (with two new clamps each end), I noticed, penciled on one side, the words "Holes on other side". Sure enough, on the other side was drawn two circles about four inches apart and the words "Two Holes". After a little research in the Yanmar Operation Manual, I discovered that they refer to this device as a "waterlock". They also are quite specific as to placement (distance below mixing elbow), on a new installation, but they make no mention of the of the holes or their position. Since it was significant enough to someone to mark, I suspect it is important but I don't have a clue. Holes up, down, or sideways? Anyone help?Donh25.5

 

[Gordon Torresen]

Holey waterlock

The pencilling sounds like your boat might have been involved in some sort of prototyping. Were there actually holes where it was marked "two holes"? Most waterlock mufflers have plugged drain holes that are not always accessible. They are generally not required, even for winterizing.

 

[Don McCoy]

Thanks Gordon

I appreciate your reply to my puzzlement. I did not notice any sort of pluged holes. The muffler/waterlock appeared to be rather crudely and thickly coated with the same sort of dull "gelcoat" that the inside of the hull has on it. It might be covering sealed holes but it appeared to me that the drawn holes were indicating where holes in the ends of the 2" inlet/outlet pipe were located, inside the wall of the 5" or 6" diameter muffler. I didn't inspect it that close as I already had it re-installed and was tightening the clamps when I spied the penciled words and circles. I rotated it several time looking for any clues as to which side had been up but had no luck. I guessed that the holes were intended to be either up or down, so I left it with them on the side. That way maybe I wouldn't be completely wrong. So far it doesn't seem to affect how it sounds or anything, but I have not placed it back in the water yet. After pondering on this situation, I will probably end up turning the "holes" so that they will be up and into any exhaust bubble that is trapped inside the waterlock/muffler. That seems to me how it might be, in order to work as a waterlock. That will be the way I leave it until someone convinces me otherwise. Thanks for your attention and if you, or anyone else has any theories, I would like to hear them.