when I was in the boat but the fellow in the slip behind me commented one day that it sounded like a tractor when I started it up. I checked it out and he was right. If yours is like mine, you don't get the swish, swish like a water lift exhaust. You just get the water running out the back in a constant flow. Mine started to fail at a couple of the welds and was leaking so I was getting salt build up on the hull back in an inaccessible place. I had to pull the three sections out and after I went to all the trouble there was no way I was going to put it back. The water lift system turned out to be more quiet and of course lighter by 20 pounds. If you end up with a vented loop, may I suggest that you remove the little rubber valve and replace it with a 1/4 plastic tube? I held the tube in with a 1/4 in o-ring compressed when I tightened the cap back down. I then tapped into the side of the cockpit drain (1/4 inch pipe) and installed a brass fitting that accepted the 1/4 inch tube. That way the little rubber valve doesn't salt up and block the hole. I had one fail and ended up with the engine FULL of sea water. With the tube there is no way you will end up with a vacuum that causes the water to flow back to the engine.