Engine Flush while boat in water?

[wschrade]

Hello everyone, so my question has to do with those times the boat doesn't come out of the water, like when we get back after the marina is closed. (Talking about a 2021 Yamaha 275 SD)

Can you fresh water rinse the engines while the boat is still in the water? If not, how concerned should I be about this? I probably stay out later than the marina staff once a week, which puts me into a situation where I use the boat twice before getting a flush in. How big a deal is this?

Thanks for your collective input.

 

[NewBoater]

Not a big deal at all. Just flush within 3-5 days if you can. Most important thing for me though is once it’s pulled from water and salt starts drying on everything it needs a flush soon. I use salt away for 1 minute after a fresh water flush for 5 minutes for engine as we boat in salt water. If it’s sitting in the water for a few days not end of the world but for me when it’s out of the water I’m cleaning it and flushing it. So salt don’t crystallize and dry up.

 

[Beachbummer]

You can flush the engine in the water, but you must block the flow of cooling water from the pump. You can either pinch the line or install an inline valve on this water path so you can close it when flushing on the water.

This is the same hose you must pinch if towing above idle speed with an engine off, so they are also known as tow valves.

Search Tow Valves on the forum to get all the details.