Hello fellow sailors,
After my boat was hauled out last fall, I was winterizing the engine in the same manner that I always do. I take off the raw-water hose from the thru-hull and stick it in a jug of anti-freeze. I run the engine until anti-freeze spits out the exhaust and then I shut 'er down with fogging spray. This year, just as I was observing the anti-freeze start spitting out the rear, a guy ran over from somewhere in the lot to tell me that had a significant stream of anti-freeze flowing out of the shaft seal. I climbed down to observe the same. There was at least as much coming out the shaft seal as the exhaust port on the transom.
I have a 1990 Canadian Sailcraft 34 with a Universal M3-20 engine.
It took me a while to wrap my head around this, but here's what I can say for sure:
(1) I have a dripless shaft seal, and the very teeny-tiny hose coming off is connected to the raw-water circuit near the anti-siphon loop, between the heat exchanger and the exhaust mixing-elbow.
(2) I've owned the boat for a few years, and always felt that the amount of water coming out the back of the boat seems to be about half of what I would expect it to be. So it's possible that this has been ongoing for a number of years. I have never encountered any overheating issues despite occasionally running the engine hard for long periods of time.
(3) I am certain that the water pump is working fine as it's a new Oberdorfer and after installation last season, I had pulled the hose off of the far end of the heat exchanger to ensure the flow is good.
I need all your input here. I'm assuming that a blockage somewhere is causing enough back-pressure that the antifreeze was getting pushed backwards through the teeny-tiny hose near the siphon loop, down and out through the shaft seal, rather than through the monstrous-sized wet-exhaust hose that is connected to the mixing elbow.
Should I presume that the mixing elbow is the culprit, and seek to replace this part? Would you bother checking or replacing anything else?
Should I leave the dripless-shaft hose connected to the raw-water circuit, or disconnect it and hoist it above the water-line?
Should I do anything to inspect the integrity of the shaft seal?
Thank you all for your input,
Graham
Kingston, Ontario
After my boat was hauled out last fall, I was winterizing the engine in the same manner that I always do. I take off the raw-water hose from the thru-hull and stick it in a jug of anti-freeze. I run the engine until anti-freeze spits out the exhaust and then I shut 'er down with fogging spray. This year, just as I was observing the anti-freeze start spitting out the rear, a guy ran over from somewhere in the lot to tell me that had a significant stream of anti-freeze flowing out of the shaft seal. I climbed down to observe the same. There was at least as much coming out the shaft seal as the exhaust port on the transom.
I have a 1990 Canadian Sailcraft 34 with a Universal M3-20 engine.
It took me a while to wrap my head around this, but here's what I can say for sure:
(1) I have a dripless shaft seal, and the very teeny-tiny hose coming off is connected to the raw-water circuit near the anti-siphon loop, between the heat exchanger and the exhaust mixing-elbow.
(2) I've owned the boat for a few years, and always felt that the amount of water coming out the back of the boat seems to be about half of what I would expect it to be. So it's possible that this has been ongoing for a number of years. I have never encountered any overheating issues despite occasionally running the engine hard for long periods of time.
(3) I am certain that the water pump is working fine as it's a new Oberdorfer and after installation last season, I had pulled the hose off of the far end of the heat exchanger to ensure the flow is good.
I need all your input here. I'm assuming that a blockage somewhere is causing enough back-pressure that the antifreeze was getting pushed backwards through the teeny-tiny hose near the siphon loop, down and out through the shaft seal, rather than through the monstrous-sized wet-exhaust hose that is connected to the mixing elbow.
Should I presume that the mixing elbow is the culprit, and seek to replace this part? Would you bother checking or replacing anything else?
Should I leave the dripless-shaft hose connected to the raw-water circuit, or disconnect it and hoist it above the water-line?
Should I do anything to inspect the integrity of the shaft seal?
Thank you all for your input,
Graham
Kingston, Ontario
