Motor Overheats, Salt Water Use.-

[Locozodiac]

When motor overheats or smokes through the peeing port soon after you have installed a new impeller or whole new water pump, have poked a plastic cannula through the peeing port with no avail, it's proper time for a full powerhead preventive maintenance.

Boaters assumes that running their motors with fresh water for long time periods on muffs, barrel, flushing ports will fix the issue, wrong, won't fix anything, not even running any motor on pure vinegar, once salt layers begins to build up on the entire cooling water system the motor had it.

This prime pic example corresponds to a Yam 15 HP motor used as an aux to push a 1.5 ton sailboat when wind is scarce, has max 100 run hours, has never been flushed with fresh water as lives permanently attached at back of the sailboat.

This reluctant boater finally understood that an internal preventive maintenance was the way to go. Don't like partial powerhead cleaning maintenances. like full ones, that's removing the entire powerhead from the pan, cylinder, thermo and exhaust covers, squirting WD-40, Carb Cleaner, pure Vinegar on every possible water path, hole and poking them with a wooden sushi stick to remove salt build ups mechanically till are impeccable clean as when factory delivered. It's the only way to assure 100% effective cooling.

Will need to order a complete gasket set, clean well all related cooling water parts, install new gaskets, torque them to factory specs with a good quality torque wrench. State of the art Norbar is my favorite brand.

Happy Boating

[jeffstevens763@g]

Disagree I keep a marine reef tank my pumps are running 24/7/365 mineral build up occurs and every so often I soak in citric acid or vinegar to desolve doing the same periodically prevents build up flushing is imperative as soon as the engine is out of the water too

[beamishken]

Originally Posted by jeffstevens763@g

Disagree I keep a marine reef tank my pumps are running 24/7/365 mineral build up occurs and every so often I soak in citric acid or vinegar to desolve doing the same periodically prevents build up flushing is imperative as soon as the engine is out of the water too

Comparison to a fish tank isnt realy a good comparison to a boat engine. As loco shows in his picture a lot of the build up in an engine isnt actually salt but expanded aluminium corrosion which can be 20 or 30 times its original size.
Whilst products that disolve salt can help and sometimes cure an overheating problem there will be times as loco shows that a full strip down is the only answer.
Modern 4 strokes are far more susceptible to this kind of thing than old school two strokes due to their smaller water pathways.
Periodic preventive flushing with a cleaning agent would probably benefit most engines but it isnt the cure all answer to an overheating issue

[Locozodiac]

Originally Posted by jeffstevens763@g

Disagree I keep a marine reef tank my pumps are running 24/7/365 mineral build up occurs and every so often I soak in citric acid or vinegar to desolve doing the same periodically prevents build up flushing is imperative as soon as the engine is out of the water too

What did you didn't understand about my post, is my English so difficult to read or understand ? The debris formation seen on pics are not metal formations as there's no loss of material due to corrosion going on, it's a form of salt hardened formation easy to clean/brush off with a Dremel rotating tool and proper cleaning bits, small bristles, metal brushes and extreme patience.

Reading your post you have never disassembled before any powerhead down, what you state is a tech fallacy. Doesn't matter if you flush any motor for hours on vinegar, acid, whatever, will only wash thin salt layers, not crusts or thinner water passages due to hard salt sclerosis build ups.

If motor has been running for long hours say 300-500 will have already collected micro salt layers one on top of the other due to repetitive On/Off - Warm/Cold cycles. It's the nature of motors working on salt water, worse if motor lives on top transom and it's never or will never be flushed with fresh water after use.

The only possible way to get 100% rid of salt layers formations already built on all internal water passages is to tear powerhed down as described, squirt pure vinegar, WD-40 on all water paths, let penetrate and scrape off mechnically all water paths with a wooden stick as not to scratch theis surfaces.

Other issues that nobody accounts for are : not all sea oceans contains the same amount of salt, the countries near the equator has more amount of salt contents as there is more water evaporation than on non equator countries. The water paths on all motors are not plain smooth ones, are kind of porous and will enevitably collect salt layers. Sea water motors cools with salt not with the green Kryptonite that car uses that keeps all water paths impeccable clean.

BTW, have tons of information and proven pics stripping motors used on salt water environments if anyone wants to continue with the theme.

Happy Boating

[jeffstevens763@g]

I fully understand what your saying even if you have broken English my point is that if you clean regular you will prevent build up that you are showing in your pictures. For your information citric acid will desolve the deposits you have if the mixture is stong enough. Acid is frightening to some but it's a natural acid from fruit when I built my reef I used rock from a sunken reef from millions of years ago built by corals from the elements in seawater the exact same elements you have in your engine it desolves it slowly or as aggressive as you want you can actularly whach it doing it. JW says there is no comparison,the common denominator is sea water so why no comparison. To be brutal if I had an engine in that state I would be ashamed because I didn't do basic maintenance. Anyway you do what you want but prevention is better than cure.

Happy boating

[Orwell boy]

so we have all flushed with fresh water ,now we need citric acid to break down the effects of years of salt ,so we have muffs ,maybe a tank and the hose non running adaptor on later four strokes ,,,,,,,assuming there is some mileage in both posters content ,then how do we present these chemicals to our cooling galleries to have some effects ,maybe twice annually ,as a preventitive ?? , thoughts on this very helpful ,could be a very interesting maintainance post ..thankyou

Happy boating

[jeffstevens763@g]

I do mine once a year with no detrimental comments from each service each year on any outboards I've owned

[Orwell boy]

Originally Posted by jeffstevens763@g

I do mine once a year with no detrimental comments from each service each year on any outboards I've owned

sorry ,maybe you have taken my post the wrong way ,i realise you are doing this as preventitive ,,and i want to try same , what i am asking is how , and with what ? what method do you use ?? ,vinigar is cheap ,maybe you fill a tank with that ? i have also seen tablets but not sure how you use them ?

[lakelandterrier]

Have to say, I've always flushed with fresh water for 5min+ after most trips (but if on amarina using daily for a week or so, not) have had no problems .

Do we take the need to religiously flush EVERY run too seriously (given in our northern latitude we may have a less concentrated saline mix.

Don't get me wrong I'm not saying ignore it, but can we over think / worry about this and the practical effects v. the theoretical one?

[neil.mccrirrick]

I think it all comes down to your internal worry meter. There are plenty of outboards sat in marina's on swing moorings being used but not flushed. Like most things mechanical imo, if you use it regularly make sure it gets to temperature it become a reliable piece of kit.

[jeffstevens763@g]

Originally Posted by Orwell boy

sorry ,maybe you have taken my post the wrong way ,i realise you are doing this as preventitive ,,and i want to try same , what i am asking is how , and with what ? what method do you use ?? ,vinigar is cheap ,maybe you fill a tank with that ? i have also seen tablets but not sure how you use them ?

Oh sorry I buy 1kg off eBay I have a decent bucket for the engine the tell tail flows back in, I just run it in that for a few hours

[beamishken]

If you look up the msds sheet for "salt away" which is sold specifically for the purpose of cleaning marine engines the active ingredient is TSP cystals which can be bought cheaply and should do the job you want
Google TSP crystals and you will find the info and suggested dilution rates

[Fenlander]

>>>Don't get me wrong I'm not saying ignore it, but can we over think / worry about this and the practical effects v. the theoretical one?

>>>think it all comes down to your internal worry meter.

My experience over several decades is with 25hp and under motors on boats kept on trailers or packed away in the case of SIBs.

Excluding Seagulls (!) I've had about 14 OBs of most popular makes. At the time of me using these OBs they have been up to 30yrs old with several previous owners and salt water use.

Only one of the 14 has suffered a degree of salt crystals build up such that it needed stripping to resolve. The other 13 have been fine with routine flushing. The problem one was a Mariner 4hp from the mid 1980s... image below.

On purchasing a used motor I always take out the thermostat... or use any similar access point to assess the degree of salt buildup.

The motor Loco shows in his OP looks like a Parsun Yamaha 15 2-stroke copy rather than a Yamaha. I noted with interest when I was looking for the Yamaha 15 2-stroke I bought recently that in some sales images you could see the grey engine paint was browned on the head due to overheating... usually on the upper cylinder. I avoided those engines.

Despite mine showing no overheating issues as something of a mid life check (it's 16 yrs old after all) this autumn I'll take the head off and the side water/exhaust plate as shown in Loco's images and see if it needs clean out. That will also give me access to replace the internal anode.

[Locozodiac]

For the posters that regularly flush their motor used on salt water soon after returning to Terra Firme, check this out.

This is my 2 strokes Tohatsu 18 HP flushed at "high water pressure" of muffs while revving forward at 2K revs for at least 15 minutes while running carb dry after each outing to avoid harmful ethanol issues on rubber parts.

The powerhead was stripped after 500 worked metered hours from brand new, this is what was found on this motor used all year round to cruise to far away distances at 3/4 to full throttle. Salt layers compromising all water paths along much less diam on every water hole located under crankcase. The anode located inside the exhaust chamber water path was nearly clogged and upper piston not spot on cooling as it should, at least the piston was not blued due to extreme temp building up on that area that was going to follow next. This motor had 0 overheating issues working that way, was running as a champ.

So flushing the motor right after motor has returned from a boating day will do little as will inevitably collect salt layers with medium to high hours use as in pic example.

Very few stripes their motors down to perform preventive maintenance on all water paths, doing so will assure correct and faster hot water dissipation, motor working much cooler compared to any salty interior motor, only checkable with a temp gauge with motor running at wot.

Everyone swears and re swears that flushing their motors soon afterwords with fresh water, pure vinegar, acid, will account to have an impeccable water circuit, well that's the theory, on real boating practice that won't happen and none of the posters that provided an answer on this theme have personally stripped their motors down to swear by that idea.

A preventive maintenance it's not a corrective one, why are so many boaters afraid of performing a DIY one. Been doing this PM for the past 15 years on all my motors with excellent results.

Happy Boating

[Fenlander]

>>>Everyone swears and re swears that flushing their motors soon afterwords with fresh water, pure vinegar, acid, will account to have an impeccable water circuit, well that's the theory, on real boating practice that won't happen and none of the posters that provided an answer on this theme have personally stripped their motors down to swear by that idea.


I don't think any of us are claiming an impeccable water circuit... but an acceptable one is sufficient.

Perhaps you miss the point in my example that 13 of 14 motors didn't need stripping as they never suffered any performance issues related to overheating. To be totally truthful 2 were new and used for 1 and 2 years respectively so we'll discount those. The average age of the remaining 12 was 22yrs old.

So my own stats are that 92% of motors that averaged 22yrs old were running and cooling fine without removing heads etc to clean the waterways.**

**Still looking in my Yamaha waterways this autumn but I'm an atypical owner.

[jeffstevens763@g]

The block anodes are checked on the services my engine is 4 years old no salt/mineral at the anode

[Poly]

Originally Posted by Locozodiac

This is my 2 strokes Tohatsu 18 HP flushed at "high water pressure" of muffs while revving forward at 2K revs for at least 15 minutes while running carb dry after each outing to avoid harmful ethanol issues on rubber parts.



So flushing the motor right after motor has returned from a boating day will do little as will inevitably collect salt layers with medium to high hours use as in pic example.

I don’t like to conflate correlation and causation, especially with n=1, but have you considered that you have a non standard flushing routine and are the one reporting bigger crystal build up? Are you in a hard water area? If so, it feels to me like revving your engine hard whilst flushing for a long period may actually make things worse. I’m not going to type the whole chemistry lesson on the phone... but it would be interesting to know what’s causing your build up. Calcium carbonate (scale) and salt are different problems. I suspect this is part of the reason manufacturers are increasingly moving towards flushing ports rather than muffs.

[Locozodiac]

Will not delve more deeply into the theme as it's very complex and each boater will have their own theory about it. Will say that the whole issue with motors overheating on salt water is related to where your boating area is located (the amount of salt contents) and the number of worked hours metered with an hour meter whether low, medium or high hours use done on X number of years.

There's more components than just calcium carbonate found on salted oceans. There's not an issue flushing any motor running at 2K or higher rpm while motor revs at load geared forwar. I happen to count with a tachometer installed side to my throttle grip to check that out. Flushing at faster rpm assures a better higher water pressure passing through all water paths compared to slow idle flushing as per what the Owner's Manual states.

To state than on an older used motors, say a 10-22 year oldie will find impeccable water paths is relative. Will dare say that none of the guys that have replied with a post have installed an induction hour meters since day one to know exact run hours. It’s not the same a 20 year old motor with low hour use and a similar oldie one with high run hours. The latter will have collected more salt layers on the entire water paths. Run hours is key, not elapsed years.

All motors counts with 2 lower leg water intakes, not all motors have flushing ports located on their powerhead, nor a tendency for all HP and their brands to count with one, for that venture will need to buy a flushing adapter. The issue about flushing through flushing ports that counts with screw type nuts located on them is that when constantly unscrewing and screwing nuts back in will end screwing prematurely the nut washers and threads located on the ports which has happened, bad music.

Be advised that if motor overheats severely when running full wot will warp the cylinder head badly, screw all gaskets and even melting electric cables lying around the powerhead area. A DIY water path maintenance changing all powerhead gaskets for new ones only costs no more than US $ 70.00, don't know about UK costs.

Flushing with fresh water, vinegar, acid, Salt Away, will only work well to remove small salt formations, but if water paths are severely compromised, that's already blocked such materials won't work as water will not recirculate properly through all water paths to soften huge salt crusts built ups which will inevitably must be removed by brushing-off, scrubbing, poking hard those water passages.

There's an interesting video from an Aussi mechanic guy called Stu, check and draw your own conclusions.

https://www.youtube.com/watch?v=8w_o5xB8ZFI

BTY, don't see any severe crust formation on any of the parts water paths shown in the video, it's more of a cleaning procedure by hard brushing than any other thing.

Happy Boating