Extend Your Outboard’s Life: Fresh Water Flush!

Now why would we want to fresh water flush our trusty Tohatsu outboard?  I dunno, David got this idea almost 15 years ago that flushing all the salt out of the outboard before leaving it for an extended period sitting on the rail would make it last longer.   When we returned to Burnt Store Marina, we noticed that all the fishermen were routinely fresh water flushing their outboards after being in the salt water.  Hmmm… if it’s good enough for them, maybe we’ve been doing something right all these years.   Regardless, our trusty Tohatsu 8 hp 2 stroke is now 12 years old and going strong.  We’ve had to replace the bracket holding it to the transom of the dinghy, tune it up and routine maintenance, but nothing major.

Here’s a photo essay on how David fresh water flushes our outboard before we leave the boat every year:

1.  First you have to buy this earmuff funny looking thingy at any West Marine, Home Depot or WalMart.  It’s officially called an outboard motor flusher in the West Marine catalog.







Next you have to attach the outboard motor flusher.

Fit the outboard motor flush clamp over both sides of the water intake.

2.  Clamp the  outboard motor flusher  around the spot on the lower unit that normally sucks in cooling water (salt water when it’s in the water).   Then attach a freshwater hose as shown (don’t turn on the water yet).

Attach the gas hose.

3.  Attach the gas hose.  Turn on the hose water and then start the outboard.  It will run as normal, except it’s sucking fresh water in through the system to flush out all the salt.  Let it run a few minutes to get the fresh water thoroughly circulated through the engine.

Disconnecting the gas hose at the gas can.

4.  Then disconnect the gas hose at the gas can.   The outboard will continue to run as long as it’s sucking gas out of the gas line – which gets all the gas out of the hose as well as the outboard.

Let it run until the outboard sputters to a halt.

5.   Let it run until the outboard sputters to a stop — it’ll sound a bit raggety at the end as it’s losing gas, but that’s OK.

6.  Turn off the hose & take off the clamp and you’re all done!   Now your outboard will be happy with no salt inside to corrode from the inside out!   And it should last longer too!

Anyone else do this differently?  We only do it once a year – when we put the boat away for the summer.  Usually we’re not near a fresh water source at a dock to make it easy to do, otherwise we might do it a couple times a year.  Other input?  Please leave a comment and share!   Cheers!   Jan



  1. My wife and I were looking into getting a boat for next year. I didn’t know that you only have to rinse the engine out once a year. This is good to know before we get it.

    • Hi Scott! Rinsing more often is DEFINITELY a better practice, but when you’re cruising and have limited fresh water, rinsing it when you can is better than never fresh water rinsing! Get the salt out! Cheers — Jan

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