Using antifreez to flush and clean outboard water jackets

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Horizons

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Hi everyone,

I bought a 6 hp Yamaha about 6 months ago, just over the last month have really had a good chance to test it out. Seems that water does come out of the tel tale peehole, at first the stream is strong, but after about 1 min it goes to a spray , then just a dribble, at that point if I just stick a piece of wire in the tel tale water starts to stream again 100%, then after some random time, 30 sec to 2 min, the stream starts to get weak again. Have taken the lower unit off, checked Impela, looks in perfect condition with hardly any sand in the local area.Checked both water jackets, front and side plates, inside is not spotless, but iv seen worse.Also the screen at the lower unit is 100% clean and unclogged. While im testing the pee stream I would like to note that the shift gear is in Neutral.

I was told by a local mechanic that I could use antifreez to clean all water ways inside the engine by diluting the water that im using to flush the engine out with. Has anyone had any experince with this possible solution? I cant think of any other reason why the pee stream is getting weak other then after sticking a wire in the pee hole after some time more sand is clogging it up, its only a small tel tale peehole, im sure it would not take much to clog it up. The water jackets did contain some sand, not 100% clogged, not even 10% clogged, but there is evidence of sand
 
Horizons said:
Hi everyone,

I bought a 6 hp Yamaha about 6 months ago, just over the last month have really had a good chance to test it out. Seems that water does come out of the tel tale peehole, at first the stream is strong, but after about 1 min it goes to a spray , then just a dribble, at that point if I just stick a piece of wire in the tel tale water starts to stream again 100%, then after some random time, 30 sec to 2 min, the stream starts to get weak again. Have taken the lower unit off, checked Impela, looks in perfect condition with hardly any sand in the local area.Checked both water jackets, front and side plates, inside is not spotless, but iv seen worse.Also the screen at the lower unit is 100% clean and unclogged. While im testing the pee stream I would like to note that the shift gear is in Neutral.

I was told by a local mechanic that I could use antifreez to clean all water ways inside the engine by diluting the water that im using to flush the engine out with. Has anyone had any experince with this possible solution? I cant think of any other reason why the pee stream is getting weak other then after sticking a wire in the pee hole after some time more sand is clogging it up, its only a small tel tale peehole, im sure it would not take much to clog it up. The water jackets did contain some sand, not 100% clogged, not even 10% clogged, but there is evidence of sand
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Antifreeze sound like a complete waste of time, and I designed plants to make antifreeze and glycol.

Circulating an inhibitied acid cleaner is smarter. CLR (lactic acid) is good in the US.

First though, catch some of the particles that are coming out of the tell tale. If they are white (lime) clean away. If they are black (bits of the impellor) you need to pull the lower unit and replace the impellor. If bit clog up the motor, you have problems.
 
Firstly

I’m a big fan of antifreeze use for winterising marine engines...but only really in an inboard, like the VP and Mercruiser gm raw water cooled engines. On these, you can fill them with antifreeze over the winter, not only protecting from freezing, but almost completely reducing the main ingredient for oxidisation or rusting...oxygen.
On an outboard, it’s about impossible to do this
More to your point, I’m oretty sure anti freeze flushing wont do what you want it to do. Salt away is a product that claims to however.
I could probably add that having an obsession for pretty much all things 2 stroke outboard related, I’ve had and still have many small outboards from 2hp to 10hp. 3 of which are Yamaha which had the same problems you have after use, then storage after salt water use. Usually a bit of wire up the tell tale, then outlet on the head a few times will clear it after a wee while. It’s basically just crystallised salt lumps that work their way through and eventually out the tell tale.
The best solution would be to try and flush with fresh water after each use in salt. Not always easy or ideal I suppose. Also worth noting that these Yamahas are built to last and take these things in their stride. To date, I’ve never heard of one rusting through and beyond use.
 
thinwater said:
Some study information regarding chemical cleaning of outboards.

http://sail-delmarva.blogspot.com/2018/05/sour-milk.html

View attachment 71765
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Interesting table. Does aluminium mean the pure metal? I find that aluminium alloys, particularly the 5xxx series, are very much more resistant to attack than 1xxx ones.

Photo shows a masthead antenna bracket with a stainless steel fitting. Bracket is a 5xxx alloy, fitting was cemented in by carbonate salts. I freed it using dilute HCl and the bracket was not attacked in the slightest.
 
I had the same issue with an 8hp Yam. Solution was two-fold:

1. Remove engine cowl and disconnect the pee-hose from the plastic outlet. You can then remove the plastic outlet and clean it, which will get rid of the piece/s of grit that are probably trapped within. The outlet has a tiny exit hole and it doesn’t take much to block it.

2. Flush with fresh water after using the engine in salt water, to prevent salting-up of the cooling channels.

Welcome to the forum and good luck.
 
Recently someone suggested using Coke a Cola which I duly did by injecting it into the peewee hole that had become blocked and no amount of poking with a piece of wire would free off. I tilted the engine and injected two or three syringe full and within a few minutes it was clear.
 
This may seem a stupid solution, I cleared a 3.3 evinrude 2T out by placing the engine in a big bucket of boiling water with Calgon in it and running the engine for half an hour, after first checking the impeller and pee hole, it worked!
 
Im going to have a chance to work on the engine this wed, im going to use a combo of what iv read, ill let you know how it goes.
 
Horizons said:
Im going to have a chance to work on the engine this wed, im going to use a combo of what iv read, ill let you know how it goes.
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A mixture of antifreeze, hydrochloric acid, lactic acid, Coca-Cola, Salt Away and Calgon all dissolved in boiling water?

My preference would be either Rydlyme or a sulfamic acid based descaler such as Fernox DS3. Perhaps you could add those to the mix if they are to hand.
 
VicS said:
A mixture of antifreeze, hydrochloric acid, lactic acid, Coca-Cola, Salt Away and Calgon all dissolved in boiling water?

My preference would be either Rydlyme or a sulfamic acid based descaler such as Fernox DS3. Perhaps you could add those to the mix if they are to hand.
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ill try vinegar mixed with fresh water first, then go from there, if vinegar/coke doesnt work, ill just flush it out with fresh water after then buy Rydlyme, the people at Rydlyme just got back to me telling that yes I can put their solution in the flush out water tank and flush the engine out with the Rydlyme.
 
Horizons said:
ill try vinegar mixed with fresh water first, then go from there, if vinegar/coke doesnt work, ill just flush it out with fresh water after then buy Rydlyme, the people at Rydlyme just got back to me telling that yes I can put their solution in the flush out water tank and flush the engine out with the Rydlyme.
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In fact, if you look at the data in my earlier post, vinegar is by far the most damaging per unit scale removed of the inhibited acid cleaners. That it is safe is myth. The common sense is dead wrong in this case. Vinegar is a lousy acid cleaner and should be saved for salads. The main ingredient is not used in any commercial cleaner for good reason. It doesn't work!
 
I just saw that, ill have another read over

iv heard people use drain cleaner before, but im abit worried that might be too strong and might damange some seals
 
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Horizons said:
I just saw that, ill have another read over

iv heard people use drain cleaner before, but im abit worried that might be too strong and might damange some seals
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Drain cleaner is ALL WRONG (acid vs. base). It will eat the aluminum really fast and not touch calcium scale one bit. That is a very poor choice and the they are lucky the engine survived.

I do a lot of testing for sailing mags and my prior experience was in refineries. We did a lot of chemical cleaning.
 
Vic S is the one of the forum’s most knowledgeable outboard experts, and one of the most respected. I would take his advice before you risk ruining your outboard with harmful reagents.
 
There might be some benefit from the antifreeze, not from its glycol or whatever it's based on, but from the corrosion inhibitors that are added to it.

But I would suggest first running with plenty of fresh water, at proper operating temperature.
To get rid of any actual salt.
Then maybe some central heating descaler/cleaner.

But the pee hole is the first thing to clog, it's common to need to clean it with wire or similar on many motors. The cooling water is not filtered terribly well and all sorts of weed, sand, debris gets in.
 
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