PlayDate
Well-Known Member
Generally speaking a siphon break only helps in one direction which is providing an air break to the right of the siphon break in the image below. The hose on the left side of the siphon break is blocked by the impeller so the siphon break does nothing for it. I can't speak to whether it actually helps or not. My Quicksilver was not installed with one but it's replacement, a Westerbeke, required one. It is possible they wanted the line to release the column of water into the elbow but from an engineering point of view....it doesn't look like it makes a lot of difference.
The image below does a great job of showing how water can fill the muffler and the exhaust hose causing water to flow back into the engine well before it finds its way outside the boat. The siphon break will not stop that from happening. The take away is to temporarily close the seacock if you are running a compression test or are having a hard time starting the generator.
The image below does a great job of showing how water can fill the muffler and the exhaust hose causing water to flow back into the engine well before it finds its way outside the boat. The siphon break will not stop that from happening. The take away is to temporarily close the seacock if you are running a compression test or are having a hard time starting the generator.