Flushing Out Salt Deposits Inside Outboard Motors

S

Sea Wolf

New member
On another thread here, the question about how best to remove salt accumulations on the inside of outboard motors came up, so here's the question:


"Will simple fresh water flushing, on a regular basis, dissolve salt deposits in an outboard motor, or do those deposits, once formed, resist simple dissolving with fresh water, and gradually accumulate anyway, and, if so, what is the best way to go about removing them, and what products or chemicals are best suited for the job?"

We've got some very sharp C-Dory owners, outboard mechanics, and dealers on board here, and should be able to get some pretty good answers, though I suspect there are a lot of complicating issues to a fairly simple question.

Thanks!

Joe. :teeth :thup
 
I use Salt Away. Run the motor at idle for about 5 minutes with the Salt Away dispenser inline with the garden hose to the flushing nozzle of the outboard.
 
Any idea how well Salt Away works? I soaked a salt encrusted thermostat for a week in a strong solution of the stuff. It took 3-4 days for the crud to clean up. Does 5 min work?

Boris
 
The reason I asked this question was that I sensed that simple flushing was obviously not getting the salt out of motors, at least in some instances.

If the salt in the ocean was nothing more than table salt, or sodium chloride, I don't think there would be any problem, as it is extremely soluble in water, and regular freshwater flushing should dissolve it away.

The problem may be that ocean salt is many different types of salts combined into one big "soup", some of which are not as soluble as sodium chloride.

What I think happens, is that some of those salts, once they get deposited on the innards of an outboard motor, don't easily re-dissolve back into water, even into freshwater, and that some form of chemical treatment flushing should therefore be in order, and, if so, one would need to find the most effective agent for the job, and our experiences should tell us what works best.

But then, I could be all wrong (again!)...... there may be a temperature issue, or one involving dissolved /suspended organics inhibiting solubility , or something involved in the electromotive issues with the aluminum alloys of the engine, etc.

Nothing, it seems, is ever all that simple, opnce you look closely at it.......!

Joe. :teeth :thup
 
C-Hawk":320tilib said:
I have a salt-away dispenser, but I use white vinegar. Works good, and a whole lot more cost friendly.
Click to expand...

Interesting; Vinegar actually helps to remove salt deposits? I took a glass of vinegar and added a spoon full of salt, it dissolved.

Pricing Salt Away in the WM catalog, not cheap but if it extends motor life and works on the boat trailer than it’s definitely worth the price. Then again, if vinegar works as well what dilution factor should I use?

I keep a pump sprayer in the truck to rinse the trailer after launching because it will sit for 2 to 4 days on average; vinegar is about $2.00 a gal at Costco so I could use it straight; it also helps remove rust.

131 uses for Vinegar

I remember using vinegar to etch aluminum prier to painting on a fishing boat that indicates it dissolves aluminum…maybe not a good idea on outboards.
 
Joe,

I have asked our Yamaha mechanic and also researched this in the yamaha literature. Their recommendations are for an immediate flushing with fresh water, and not just a splash. Turn up the pressure to be equal to if the engine is running, and flush for 15 to 20 minutes. That is with just freshwater. If using Salt-away, it decreases the time by half according to the mechanics.

That works great for an out and back day, but if you are out for 3,4,or more days, it bothers me that it doesn't get rinsed until the end of the last day. Don't like that much.

Good thread, thanks for bring it up and hope we get some good info. Lots of good sources here.

Harvey
SleepyC :moon
 
hardee":23exhclu said:
...but if you are out for 3,4,or more days, it bothers me that it doesn't get rinsed until the end of the last day. Don't like that much.
Click to expand...
Will salt accumulate or build up if the the cooling jackets of your outboard are kept full of salt water? Doesn't seem to me like there'd be any more build up than you see on the hull after a few days, or on the dockside.

So I think as long as you kept the cooling jackets full of salt water, you'd be okay until you got home to flush. But then I'm not a mechanic, I just stayed at a Holiday Inn one time. ;)
 
C-Dawg":1qs1r4ds said:
I use Salt Away. Run the motor at idle for about 5 minutes with the Salt Away dispenser inline with the garden hose to the flushing nozzle of the outboard.
Click to expand...

I seem to remember that somewhere someone said that the flushing attachment was not to be used while the engine is running. Can anyone definitively confirm or deny?

Thanks,
Warren
 
Joe

I've wondered too about the fresh water running removing the old salt. Our twin Honda 40's spent the first 250 hours of their 1200 hours on the ocean and since more time in fresh water then salt. Only problem so far with areas the salt could have effected is having to replace thermostats. One thermostat change out in 9 years running seams good to me salt or no salt. Fortunately when the one thermostat stuck it was in the open position and for a while that was trouble enough. Have bought the kit to replace the impellers and plan to it soon as the weather warms here. Will be interesting to see how much corrosion is in that area.

No problems with motors overheating in the seven seasons we have cruised the boat even though we lugged them somewhat with props not properly pitched at times for loads and altitude in the first two seasons.

Jay
 
I changed out thermostats last year, and there was quite a build up of salt in those lines. The shop I use said they see this all the time, and used muriatic acid to flush that! :shock: There was quite a bit of nasty stuff that came out of there. This was, according to them, as per Honda's recommendations. I certainly got a much stronger pee stream after that. When we're out cruising, we may go weeks or even months without access to flushing. Generally daily running, though.

I've asked some of the commercial guys around here who run outboards about flushing... "What? Almost never." I take that to mean: never. When we're home, I flush after each outing most of the time.

We use vinegar on our windows and eisenglass to cut through the salt when we're out cruising and don't have access to unlimited fresh water. We keep a squeeze bottle with a mixture of vinegar and water handy... squirt it on the windows and run the wipers as necessary. Vinegar is definitely your friend.

Best wishes,
Jim B.
 
Doryman":19lfrjpd said:
I seem to remember that somewhere someone said that the flushing attachment was not to be used while the engine is running. Can anyone definitively confirm or deny?

Thanks,
Warren
Click to expand...
Warren,

The owner's manual for my Merc states to run the engine at no more than idle while flushing to reach operating temp. I assume this opens the thermostat and flushes fresh water throughout all the jackets.
 
My Suzuki manual specifically says you are not to run the engine using the flush ports. I only run the engines with the outdrive dunked in a tub or in the ocean. I use a hose attachment (engines not running) at the end of each trip.
 
My 70 HP Suzuki had salt deposits when i bought it...the pee indicator was very weak.I brought it to the dealer because i thought i may need a new water pump or impeller. Mechanic said both the water pump and impeller were good and that he had to clean the lines from salt deposites. He did mention Salt Away but said if i had the dispenser that CLR ( Calcium,Lime, Rust remover ) for plumbing would work just as good.I would of thought the CLR would be kind of strong to use in the cooling system. Tug
 
Doryman":1nbfx761 said:
I seem to remember that somewhere someone said that the flushing attachment was not to be used while the engine is running. Can anyone definitively confirm or deny?

Thanks,
Warren
Click to expand...

If you use the "rabbit ears" on the lower unit to flush with --- run the engine at idle.

If you attach the hose to the flushing port (like on my Honda 90)- do not run the engine.

(check the owners manuel for your engine)

I fill the flushing bowl with vineger and let the water dilute it.
 
Several years ago my O/B guru told me that a major source of salt buildup was from tipping the motor up as soon as you stopped it. This trapped water at specific points within the cooling jacket while the engine was still warm, and these sites were where salt accumulation occurred. That was for a small 4-hp on my sailboat. What I did after that was allow the O/B to cool, lift it vertically by the mount to drain, and only then tilt it. I've kinda followed that as best I can with a 90-hp, that cannot be lifted up. I idle the engine for a few minutes to be sure it is as cool as it will get, then shut it off and let it finish cooling with the prop in the water. Then I raise it incrementally, letting it drain what it can until it is all the way raised on tilt. He also told me that salt flushers were "soda ash" (whatever that is, and was not good for the engine. Soda ash sounds suspiciously like lye or KOH, either of which will dissolve aluminum while producing lots of free hydrogen :shock: !! Flushing your engine with the hose connector runs water backwards through the cooling system, which is why you should not run the engine while flushing that way. Sleepy-C has pictures of this flush technique.
Rod
 
I flush with a salt away solution poored in a flush bag, then I run the engine till the gas is out of the carb and call it good. I do this after each time out usually within an hour of trailering the boat.

I switched from rabbit ears a few years ago. I believe the immersion of the lower unit into the bag simulates it being in the water and I get a better flush.

I also wash the trailer rails on the inside with a hose used for watering plants with a salt away solution and wash the entire boat after each outing, flush the wheels and brakes to with the same.

This helps with the salt build ups.

If left moored I would try to flush with fresh water after each use and then if safe leave the motor tilted up out of the water.
 
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