[ndutton]

I have not noticed an exhaust-y odor in the boat since the installation of the drain system. However, I'd be interested in the details of yours to see if there's a difference from mine. But remember, I'm not convinced such a drain is necessary. There's only a quart of residual water in the muffler after shutdown. It's just not significant.

Here's a picture of my vent hose where it attaches to the galley sink drain plumbing: