Yanmar water backflow
This has happened twice within the week. Upon shut down of our 3 cylinder Yanmar, it syphons water back into the manifold, preventing the start of the engine. The first time was a four hour search. Today the diagnosis was much quicker. Both times the boat had six adults aboard and the wet exhaust outlet would have been under water. I don't want to tell all our guests to move to the bow so I can shut down!! I am getting good at sailing in the harbour.
The exhaust line appears to have an upward loop--like a sink drain, but that doesn't stop the backflow. Can a check valve/anti syphon be installed? I recall seeing a flap on the hull of an exhaust outlet-I assume to prevent this issue.
Any help appreciated
Bayfield 32 Sea Alles