Salt Build up in Suzuki Powerheads

[a64pilot]

Originally Posted by Simi 60

Seems this is a 4 stroke thing?

I think so, cause I never remember any internal anodes back in our older Mercury “Towers of Power” as a kid growing up.

I don’t understand why an internal anode is needed, seems like the external would protect the whole motor?

[Cheechako]

I've not had a small outboard that didn't clog with salt when left sitting unless you flush it prior. Almost every time they sit , they wont spit water out when started later. No, it isn't just "sea creatures" salt builds up. But I do think the culprit is lack of use in most cases.

The anodes are for corrosion protection, not to combat salt buildup, which they wont do.

[catsketcher]

I don't have Suzukis but my cat is powered by one 9.9 and one 25 hp four stroke Yamaha (she is that way because I don't need the power of 2 25s but need more power than 2 9.9s).

I have been outboard powered for 19 years and have flushed my now 15 year old 25 about 4 times when on the slip. I was worried about flushing until a mate pulled apart a series of ten year and more 9.9 Yammies off cruising catamarans (which almost never get flushed). The insides were very clean of salt. The way he heard, from an outboard mechanic, was that getting a motor to operating temperature and keeping it there allows time for the block to heat up and increases the temp of the flushing water. As a school science teacher one of the experiments I get kids to do is to see the effect of temperature on solubility of salt.

Heating water will increase the ability of water to dissolve salt and other crystals. So getting your motor to operating temperature and leaving it there for a long time should help flush the innards of crystals.

The only motor I had where the galleries got chocked with salt was the 15 hp Mariner on my trimaran. I only ran it for very short times so in my very small sample size this idea seems to work out.

Give the thing a long run and this may help it stay clean inside.

Also I have had one issue with a telltale blocking on the 9.9, so work out how to remove and clean the telltale.

[lazydove]

i own a suzuki 15 hp four stroke, get me home engine, 10 years old, very low hours, carefully flushed once a year. engine ran fine but no water out of telltale. big salt build-up on powerhead -.cleaned out, impeller changed - did not help. now impeller to be changed. plenty of corrosion on engine, had same problem with suzuki 250hp

[a64pilot]

Cmon guys, let’s be nice.
He misinterpreted my post, and I wasn’t clear with it either so it’s a mistake we all could have made.
Bottom line, no harm done

[thinwater]

It's not sodium chloride build up, but calcium and magnesium carbonate (limestone). The critical temperature varies with surface texture and local concentrations, but is generally 150-160F. Thus, cooling jacket temperature plays a huge role; just a little too high and you lime-up. Also, rapid shut down after running hard is a factor (cooling jackets continue to heat for a few minutes, since the cooling flow stops--this used to be a serious problem on many cars, particularly in the 70s when higher thermostats were added to reduce HC emissions, but then electric cooling fans were added and cooling systems redesigned). It was called "heat soak." So always give the motor a minute to cool down at low throttle.

Flushing with freshwater generally does NOT help very much, because by the time the hoses are attached, the engine is well below the critical temperature and precipitation has finished. It helps, just less than common sense suggests, since limestone does not re-dissolve easily.


Flushing with acid is variable. Lactic acid (CLR) gives the best ratio of lime removal to aluminum damage.


Excellent cruising topic.

[rbk]

Originally Posted by a64pilot

Cmon guys, let’s be nice.
He misinterpreted my post, and I wasn’t clear with it either so it’s a mistake we all could have made.
Bottom line, no harm done

[catsketcher]

Thinwater - where does the calcium and magnesium come from? What is the deal with the critical temperature? 30 years ago it seemed like a salty crusty crystalline substance when I pulled the cooling jacket off but we didn't taste it.

Anything else you can elaborate on, please do.

cheers

Phil

[Bruce K]

Originally Posted by a64pilot

Sorry I think you misunderstand, the engine in question is the newer 9.9 to 20 HP Suzuki, which power a whole lot of the dinghies out there.
One of the draws to this engine is that it’s fuel injected and therefore no carburetor to gum up from ethanol fuel or whatever clogs up carburetors these days.

There have to my knowledge been only a couple of engines exhibiting this symptom, making me think there is something wrong with those engines and not a design defect, or the internet would be full of failure reports.
I surmise based on mine being clean as a whistle that it could be their engines running hotter than mine as I know that can cause salt or other salt like minerals to precipitate out of solution, for this reason raw water engines run quite cool, or they too will clog their cooling passages.

Also I run the snot out of mine, often full throttle, I don’t baby it.
I don’t try to abuse it either, just I don’t take it easy.
I have never flushed it with anything except fresh water, and truthfully have only flushed when we are in a Marina.
In contrast on my old boat with a big Mercury Verado, it was flushed after each use, even if only taken to the lake to ski.
However that outboard cost about as much as a decent car too, so I was careful with it.

Suzi 9.9 to 20hp have a 5 years warranty (In Australia probably world wide) My dealer said if there are any corrosion issues he will replace the powerhead.

[Boatyarddog]

Originally Posted by catsketcher

Thinwater - where does the calcium and magnesium come from? What is the deal with the critical temperature? 30 years ago it seemed like a salty crusty crystalline substance when I pulled the cooling jacket off but we didn't taste it.

Anything else you can elaborate on, please do.

cheers

Phil

https://en.m.wikipedia.org/wiki/Seaw...rom_freshwater
Anodes are not for salt build up, generally for metal composition differences between parts that can cause corrosion.

[a64pilot]

I don’t think it’s corrosion, I know anodes don’t prevent salt or other mineral build up, be nice if they prevented barnacles though

I’m postulating that one or two engines are running hotter than spec, and that causes the mineral build up.
I was wondering if any of the problem engines changed thermostats or tested theirs, and whether or not the problem reoccurs
I know we all think that hotter water means it will hold more things dissolved, anyone who has made ice tea understands that.

However that is not always true, cold water will hold more oxygen, often in hot water fish die cause the oxygen gasses off and there is very little O2 for the fish.

[ranger58sb]

Originally Posted by a64pilot

I was wondering if any of the problem engines changed thermostats or tested theirs, and whether or not the problem reoccurs

Yep, our guy checked thermostat working fine. Replaced anyway, no change in the immediate problem; they still had to tear it down and manually remove the salt build-up.

-Chris

[catsketcher]

I looked up a table of solubility and temperature. For some substances there is not an increase in solubility in warmer water. Here are some stats

- Calcium carbonate - very low solubility and no data on temp
- Calcium Bi carbonate - more soluble as water temp increases
- Calcium chloride - more soluble as temp increases
- Calcium hydroxide - reduced solubility at high temp
- Calcium sulfate - no change with temp

- Magnesium chloride - more soluble
- Magnesium nitrate - more soluble
- Magnesium sulfate - more soluble

- and salt - Sodium chloride - ever so slightly increased solubility with temp.

https://en.wikipedia.org/wiki/Solubility_table

According to Brittanica

Chemical and physical properties of seawater. The six most abundant ions of seawater are chloride (Cl−), sodium (Na+), sulfate (SO24−), magnesium (Mg2+), calcium (Ca2+), and potassium (K+). By weight these ions make up about 99 percent of all sea salts.

So most of the salts in seawater seem to increase their solubility (or not reduce it) at higher temperatures. I am not a chemist but I do not see how water at around 70 degrees C causes salts to precipitate out. There may be some other mechanism.

Has anyone heard of a chemist testing the buildup in the cooling system to see exactly what it is?

My unproven theory is that of build up time. If you have a fast run, and often start and stop the engine then everytime you stop the engine the galleries are going to quickly dry out, especially if the motor is hot, leaving behind the salts. If you run the motor for hours at a time, the cooling system gets well flushed and if you sit at the mooring or at anchor, leaving the motor ticking over for a while, it cools down and evaporates the interior less quickly when stopped.

cheers

Phil

[sailhand]

A coastguard boat in north queensland was supplied with twin 250hp outboards by the local yamaha dealer. He asked that one motor be regularly flushed and the other never flushed. After several years the motors were stripped down and the one that was regularly flushed proved to have the most buildup in the cooling galleries. According to the dealer the deposits in the water galleries were sent for analysis and proved to be predominantly aluminium chloride. Tap water in Australia is chlorinated, I wonder if this contributes to the problem.
My experience is the lack of use of a previously well used outboard quickly leads to blocked galleries. If leaving my tender motor unused for three months or more I usually pull the head and clean the galleries out. Quite often there is a gelatinous translucent material as well as the more familiar crystalised material. I wonder to what extent paint dissapearing from the internal galleries promotes the formation of the deposits. Also is heat build up in the block that causes paint damage externally also responsible for internal paint damage. There is what appears to be a welsh plug on many outboard powerheads. In actual fact these are often there to simply indicate an overheating incident. If the welsh plug like metal disc is missing it indicates an overheating incident has occurred. Consistent use seems to be the best solution.

[Pete7]

Originally Posted by Capt JJ

Topic isn’t projected to a community well versed much less relevant in our lifestyles of this audience Imo

Valid topic but directed at such misnatched audience. Might as well a try to start a conversation about wakeboarding or jetskis

You are of course entitled to your opinion, but I for one disagree. I think there is a wealth of knowledge on CF covering a multitude of topics, stick around you might learn something.

On to the subject of the thread then. For many years I ran my own diving rib, 6m in length and powered by a Yam 115hp 2 stroke. Always flushed and stored on the trailer in a dry building after a days diving. One year i took it up to the Upper River Thames for a family holiday. A bit OTT for the upper fresh water river with a 6 knot speed limit, never the less, we did enjoy the open stretches to the full and were careful to stop for tea before entering the next lock, because they time you as we found out on the first day

Finally back home it was time for a good service which I always did myself. On taking out the thermostats I was quite shocked to see large salt crystals growing around them and in the galleries nearby. This despite daily flushing when diving and a week running around on a fresh water river.

So does flushing help remove salt? some perhaps, if it done quickly when you stop running the engine, but it isn't a guaranteed panacea. I note Volvo sell a chemical solution at a very reasonable Volvo price for flushing their engines to remove the salt which they claim is much more efficient compared to water.

Pete