salt in outboard motors

[FergusM]

We have a Mariner 2 hp outboard, and I mentioned to my wife that there were several items in PBO about the problem of salt deposits in the cooling systems of small outboards, and the difficulty of removing them. There is a council of perfection that says you should run the motor in fresh water each time you run it in the sea, but I suspect that is more honoured in the breach than the observance, especially when returning to the mooring on a wet Sunday night.

Anyway, she said there are chemicals you can add to everything from kettles to toilets to remove limescale, and wasn't there something you could use in water every now and again to remove salt deposits from outboard's cooling systems? I don't know. Does anyone have any ideas?

 

[tr7v8]

There are vaious limescale removers and I suspect some of them in a dustbin of water could help. Howeer not sure what the impellor would think of it and more importantly once these deposits have gone hard they are really solid and I am not sure any sort of flushing would make any difference.

Jim
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[longjohnsilver]

Used to have a merc 2.2 which I did flush after every uise with fresh water, still blocked up.

Now have a Yam 2hp which I rarely flush thru which has caused no problems at all. Moral is avoid Mercs and opther small engines which have been re-badged and go for the Yamaha.

 

[Joe_Cole]

I seem to remember that most lime scale removers specifically warn against using on Aluminium, which would make it a definate "No" to using them on outboards.

Joe

 

[Trevor_swfyc]

Fergus,
I very rarely used mine, the main use is the summer cruise when I take the inflatable. I always washed the outboard out in a dustbin full of fresh water, and again at the end of the season. Even so, come spring the outlet would be blocked, back flushing eventually cleared it. So to overcome this I drilled out the outlet to increase the diameter and flow. Last year on holiday it started, ran for 2 min then stopped, it just would not restart. I removed the plug to clean and heat it up, when I held it over the gas flame it was clear it was wet.
At home I removed the head to find 90% of the cooling chamber was blocked solid, water would not touch it. I had to use a small round file and the deposit was rock hard eventually got the better of it. I guess the head had warped with the heat so I rubbed the head on fine wet and dry on a flat surface. Reassembled it all and away it went again I only hope it goes ok when I want to use it.
The reason for the problem is that the salt water in the cooling chamber boils off each time after use and the salt builds up by the time it gets flushed the salt is rock hard and impermeable. I think the only answer is to take the head off at the end of the season and clean it up, spray with WD40 and assemble for hopefully trouble free use during the summer.
Good luck
Trevor

 

[Guest]

The magazine "Practical Sailor" in the US had an article about "descalers" and the simplest way to summarize the article is to say the word.... "Vinegar".

If you want to clean out an outboard.....buy a couple of gallons of cheap "white vinegar" pour it in a trash can (dust bin?) and dilute it with fresh water and run the motor in it for a little while. If you let it run for a while, replace the mixture with fresh water and run it alittle longer to completely clear out the engine.

If your boat gets particularly "salty" from a day on the water....to speed up the cleaning process....use some vinegar in a "pre-rinse".....it will dissolve and carry away the salt so that the soap or final wash will be more effective.

Only downside I can think of is that your motor or boat may smell a bit like a salad.

Rob

Reality is the cause of all stress!!

 

[enterprise]

Yes I know the problem,

Have had to strip a suzuki 2hp twice.
Buying gaskets, a very helpfull mechanic from fairweather marine told me that they drill a small hole into the circulating passages which is supposed to help.

The problem may be due more to sediment or sand from those close encounters with the beach.

The small passages make it prone to blocking easily.

Couldn't bring myself to drill the hole though.

 

[Chris_Robb]

Re: Vinegar

Vinegar is one of the best cleaning fluids around. I use it to wash down anything from head lining to the hull. It even gets rid of the appaling smells from my son's trainers - leave to soak for 1 day then rinse!!!!!

 

[Guest]

Vinigar also eliminates smells in the head by dissolving the salt around the toilet bowl, which retains odours. Use a squirt at least once a week while cruising.

 

[ArthurWood]

If it's only salt deposit, then fresh water flushing is as good as anything to remove it. If it's carbonate/bicarbonate deposit from overheating, then acid, such as vinegar is necessary, but it will have to be left in the engine overnight to allow the weak acid to be fully effective.

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[bobbyv]

Now I know this is totally wrong and I don`t pretend to know why,
but I have used my Mercury 4.0 o/b for "commutting"to my mooring(10 min.run) and occasional runabout (20 min.max) for 5 years in the Deben & locale) washing occasionally in fresh water,and have encountered no problems whatsoever!Tempting fate? You tell me!
It`s an imprecise science!!!!

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[longjohnsilver]

4hp and above seem to have fer fewer problems than the 2hp range, expect it's something to do with the size of the waterways.

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[charles_reed]

I\'d hazard a guess

That the deposit build up (which is not Na2Cl unfortunately) has more to do with the temperature that the engine reaches - so an engine which never gets really hot doesn't suffer from deposit build up to the same extent as an engine that is thrashed for long periods (10-20 minutes).

I also suspect that the problem is more marked in smaller engines, which are more likely to be worked flat out, than in larger engines - and has little to do with waterway passage sizes.

If you want to shift the deposit, use phosphoric acid, that really does work and aluminium phosphate is fairly stable (its the etching material used before painting an aluminium assembly) so it won't damage the aluminium engine castings.

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[rbrooks]

Looking at all the posts salt deposits seem to be a regular problem, my question is why air cooled motors were fased out?
if no water is drawn up their would be no deposits. or were their other problems with small air cooled outboards?

Rog

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[davey]

Yamaha are not 100%

Used to have a merc 2.2 which I did flush after every uise with fresh water, still blocked up.

Now have a Yam 2hp which I rarely flush thru which has caused no problems at all. Moral is avoid Mercs and opther small engines which have been re-badged and go for the Yamaha.

Yamaha, what a joke! I bought an 8HP twin on eBay as "Spares or Repair". Allegedly it ran but the cooling system was faulty. The seller was a foreigner, possibly Polish and the motor turned out to be a basket case. The aluminium alloy had gone porous and crumbly. The head bolts had rusted. As the bolts were only going into aluminium, low tensile bolts had been used by the skinflint manufacturer. When the previous owner tried to unscrew these, the hexagons all sheared-off. This left the head attached to the block with rusty dowels. Apparently he had then tried a hammer and chisel, FAIL. Having been quoted £350 for a new block and head (bolts gaskets and thermostat extra) its not really worth messing with it especially as the block will be inferior metal to that on a British Seagull. Evinrudes made in Belgium are good metal and so are American built Mercurys, unfortunately there are still a lot of also-ran manufacturers. As to the Seagulls, these use high-tensile bolts, studs and screws which will usually undo OK even on fifty year old motors. Caveat Emptor.

 

[VicS]

Yamaha, what a joke! I bought an 8HP twin on eBay as "Spares or Repair". Allegedly it ran but the cooling system was faulty. The seller was a foreigner, possibly Polish and the motor turned out to be a basket case. The aluminium alloy had gone porous and crumbly. The head bolts had rusted. As the bolts were only going into aluminium, low tensile bolts had been used by the skinflint manufacturer. When the previous owner tried to unscrew these, the hexagons all sheared-off. This left the head attached to the block with rusty dowels. Apparently he had then tried a hammer and chisel, FAIL. Having been quoted £350 for a new block and head (bolts gaskets and thermostat extra) its not really worth messing with it especially as the block will be inferior metal to that on a British Seagull. Evinrudes made in Belgium are good metal and so are American built Mercurys, unfortunately there are still a lot of also-ran manufacturers. As to the Seagulls, these use high-tensile bolts, studs and screws which will usually undo OK even on fifty year old motors. Caveat Emptor.

Why are you digging up and commenting on a topic that is a good 8 years old ?

 

[davey]

Air cooled outboards

Looking at all the posts salt deposits seem to be a regular problem, my question is why air cooled motors were fased out?
if no water is drawn up their would be no deposits. or were their other problems with small air cooled outboards?

Rog

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I still have an air cooled outboard. The number one snag with these is the NOISE which is much worse than a Seagull. Ocean Outboards of Southport used to make outboards using lawn mower engines but you know how loud a lawnmower is (typically 95dB or more). American manufacturers used "Wall of Water Silencing" and padded soundproof engine hoods hence they were in a different league when it came to quiet running. There are still air cooled outboards made in China. Some use an industrial diesel engine of 5 to 10 HP but the arrangement is fairly basic. There is no soundproofing so they would be fairly unpopular with ones neighbours.

 

[davey]

Is there a time limit?

Why are you digging up and commenting on a topic that is a good 8 years old ?

Hadn't noticed the date but someone may still find the information useful as hopefully engines will last a long time.

 

[savageseadog]

Why are you digging up and commenting on a topic that is a good 8 years old ?

A few thousand years doesn't stop religious debates

 

[KristiferColumbus]

Used to have a merc 2.2 which I did flush after every uise with fresh water, still blocked up.

Now have a Yam 2hp which I rarely flush thru which has caused no problems at all. Moral is avoid Mercs and opther small engines which have been re-badged and go for the Yamaha.

Just sold a merc that I used constantly for ten years & never flushed once.
Moral of the story;don't believe everything the 'experts' tell you