Brackish water and flushing an outboard

We purchased a condo earlier this year in Ft. Myers. It's on a creek that empties into the Caloosahatchee River between US 41 and I-75.
I'll be putting the center console in the water this week. This is obviously a brackish area which leads to my question. How do I find out the level of salt in the water and thus whether I should flush the engine every time I use it. Is there a chart somewhere showing this?
I've asked a couple of boaters in the marina but have gotten conflicting information.

Taste it.

I agree, taste the water.

Salt water is heavier than freshwater, so the top layers may be fresh. The Everett WA marine is brachish at mouth of the Snohomish river. The top 1 to 3 feet is fresh water depending on the time of year and rain fall. Most of the spring fall and winter months most boats are floating in fresh water depending on their draft.

Bought one for the first year to use with my Electroscan waste treatment units as I travelled the ICW....about $20. Bottom image

Measure salt water or salinity of water, ideal for aquariums and marine monitoring.
Measures on 2 scales, Specific Gravity (D 20/20) and parts per thousand (‰).
Features automatic temperature compensation (ATC)
Comes with hard case, dropper, screwdriver and cleaning cloth.
Comes with 1 year warranty with Agriculture Solutions LLC

There are several types and methods....

http://www.tfhmagazine.com/details/articles/salinity-measurements-for-marine-aquariums-full-article.htm




Instead of buying, check to see if any pet stores have one you can borrow.


I found charts for the outer banks and the Chesapeake...maybe there is something there or maybe the local Dept of Agriculture soils place might have the info or access to it.

There are millions of outboards in saltwater around the world that never get flushed, I wouldn't worry about it.

meridian said:

There are millions of outboards in saltwater around the world that never get flushed, I wouldn't worry about it.

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This. Especially in brackish. Flush it when you have it serviced. Ask around those parts, you'll see.

I owned a Johnson 70hp built in 1986 and kept on the dock in salt water for almost 20yrs. I flushed out maybe ten times, mostly when it came out for bottom paint or other work. Otherwise it might go a couple years and never get flushed. It was running fine when I sold it, still looked pretty good but some paint bubbling off.

Now I have a jon boat on the same dock, 2003 merc 8hp, likewise never flushed. Still looks good and runs fine.

I think most of the damage from salt water is in nooks and crannies that do not get flushed with the hose. Things like seized LU bolts and powerhead bolts.

When I get a new to me OB, I take out as many of the LU and PH bolts and grease them up and stick them back in. Why they don't do that at the factory is beyond me.

I'd flush it if you are going to take it out of the water and store it. Better yet, run it up the freshwater part of your river and pull it out on a ramp in a freshwater area.

Best flush you will ever get, the run up that river.

Wow...while I don't disagreee.....

Just wondering where all the rabid "FLUSH, FLUSH, FLUSH" posters are that even recommend flushing their diesels after every use!!!

psneeld said:

Wow...while I don't disagreee.....

Just wondering where all the rabid "FLUSH, FLUSH, FLUSH" posters are that even recommend flushing their diesels after every use!!!

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Christmas shopping for flush kits.

I flush every time..... oh wait, outboards. Not so much.

oscar said:

I flush every time..... oh wait, outboards. Not so much.

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Unless it's yellow. Which in some cases you just let it mellow.

Being close to the freeway were about 13 miles up from the coast.
Which is about 5 miles down river from the power plant. You'd think that would be far enough up to be fresh but we still get tidal action so I assume we get salt with it.
I like the chart in post 4.
225hp outboard motors get expensive when you replace them for no reason.

Capt.Bill11 said:

Unless it's yellow. Which in some cases you just let it mellow.

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Nope. Flush it. Keeps the "viscosity" of the tank contents at reasonable levels.

You'd think that would be far enough up to be fresh but we still get tidal action so I assume we get salt with it.

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You may well not be getting salt. Two tidal rivers I am familiar with, the Sacramento and the Hudson, have fresh water and at upper locations.

Way back when (pre1960's) the outboards could use flushing. With current outboards flushing is not required. Can't hurt, but doesn't do much good. Side note, please don't grease bolts unless done annually. The grease dries out over time and little by little, the aluminum threads cut into the case can come out with the harder stainless bolt threads.

Just keep fresh fuel/oil and ensure lower unit has clean lube with good seals and any of the big name makes of outboard will give you decades of dependable service.

mbevins said:

225hp outboard motors get expensive when you replace them for no reason.

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I wouldn't replace one for no reason.

Willow-B said:

Way back when (pre1960's) the outboards could use flushing. With current outboards flushing is not required. Can't hurt, but doesn't do much good. Side note, please don't grease bolts unless done annually. The grease dries out over time and little by little, the aluminum threads cut into the case can come out with the harder stainless bolt threads.

Just keep fresh fuel/oil and ensure lower unit has clean lube with good seals and any of the big name makes of outboard will give you decades of dependable service.

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Flushing is sort of a semi old wives tale. The need WAS real. Was being the key word. The big thing is servicing as recommended and keeping lubed and oiled. I use to know many who tilted their outboards up out of the water even on fresh water lakes. That puts water in places that it sits and ultimately can damage. Also, leads to some freezing that would have been fine in the water.

We have outboards on a center console and never flush except when it's out for full service. Then it's more just cleaning it out as it goes right back in the water. Outboards of today are really built to survive well in salt water.

The lake we were on was fresh water and well inland so no salt, but lots of minerals flowing out of the mountains and down the river. It was as bad on outboards and stern drives as salt water.

Now if you have a lift and the boat is going to sit out for a while, flushing doesn't hurt anything.

" I use to know many who tilted their outboards up out of the water even on fresh water lakes. That puts water in places that it sits and ultimately can damage"

Example...

Had a friend tilt his OB while trailering (normal). Once home, he lowered the OB to an upright position, which drained the water jackets and lower unit. The OB is ready for the winter.

However, he later tilted the motor back up for whatever reason and left it there. No problem, except the lower unit was left exposed to the elements and rain refilled the lower unit up to the prop. The winter freeze left him with a lower unit in need of disassembly, welding and reassembly. Expensive lesson learned.

Willow-B said:

" I use to know many who tilted their outboards up out of the water even on fresh water lakes. That puts water in places that it sits and ultimately can damage"

Example...

Had a friend tilt his OB while trailering (normal). Once home, he lowered the OB to an upright position, which drained the water jackets and lower unit. The OB is ready for the winter.

However, he later tilted the motor back up for whatever reason and left it there. No problem, except the lower unit was left exposed to the elements and rain refilled the lower unit up to the prop. The winter freeze left him with a lower unit in need of disassembly, welding and reassembly. Expensive lesson learned.

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I've seen the same and the mechanic would ask the owner why they tilted it and the answer was "Well, I just thought I should."

Willow-B said:

Way back when (pre1960's) the outboards could use flushing. With current outboards flushing is not required. Can't hurt, but doesn't do much good. Side note, please don't grease bolts unless done annually. The grease dries out over time and little by little, the aluminum threads cut into the case can come out with the harder stainless bolt threads.

Just keep fresh fuel/oil and ensure lower unit has clean lube with good seals and any of the big name makes of outboard will give you decades of dependable service.

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What is your basis for the statement in bold? I have greased bolts on outboards and when removed ten years later, the grease is still there. The intent is to prevent galvanic corrosion between the cathodic stainless fastener and the anodic al casting. Grease keeps water and air out and lasts a long time. Galvanic activity near zero if water and air kept out.

30 years personal experience

If the boat is in salt water when not being used, you do want to tilt the engine up; it will drain fine and not get growth on it.

You don't want to leave an engine tilted up in freezing weather...fresh or salt.

30 years personal experience is equal to 15 minutes of full time experience in the trades.... in my experience.

Exceptions to both...sure...but not all that many.

Who said anything about freezing weather? Though I have seen it done in freezing weather, including the little 40 Merc on my Whaler, here in NC on any number of boats with no consequences. Maybe you are talking about something far south of the teens, where salt water freezes, or very old engines? I suspect the latter.

caltexflanc said:

If the boat is in salt water when not being used, you do want to tilt the engine up; it will drain fine and not get growth on it.

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This has always been the case in my world. Salt or fresh. However up on the Great Lakes once you started to see freezing nighttime temperatures the motor stays in the water.

Ocean water freezes just like freshwater, but at lower temperatures. Fresh water freezes at 32 degrees Fahrenheit but seawater freezes at about 28.4 degrees Fahrenheit, because of the salt in it.

Can the ocean freeze?

To be fair to the OP....


The averaged salinity in the global ocean is 35.5 PSU, varying from less than 15 PSU at the mouth of the rivers to more than 40 PSU in the Dead Sea.

So tell me fellas, why is having half of your lower unit in the water better than having it drained and out of the water? So all those dry stack and trailer storage people should scurry and stick their motor in the water when it's cold? My gosh how do those thousands of motors survive all those years?

caltexflanc said:

So tell me fellas, why is having half of your lower unit in the water better than having it drained and out of the water? So all those dry stack and trailer storage people should scurry and stick their motor in the water when it's cold? My gosh how do those thousands of motors survive all those years?

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Angle

'Drained' is the key word. If tilted up after drained, it better not be open to the elements...