SeaFoam use in oil or gasoline???

[n5ama]

I’m told that a product called “Sea Foam” is helpful as a additive for both fuel and oil. The stuff is available in most auto supply stores but not real cheap. My boat is powered by a 10hp 4cy outboard.

What is the cruiser’s take on its use?

Thanks

[a64pilot]

What are you trying to do with it? If clean the carb then I wouldn’t put it in the oil.
If you put it in the oil, I’d be careful with how much as it of course will thin the oil a good bit, and I wouldn’t leave it in for a full oil change interval, maybe add it towards the end of the oil change interval.
I don’t use high detergent additives myself, I believe they are intended to clean up a problem that shouldn’t have been allowed to happen, like sludge in your oil for example.
If they worked to clean carburetors, with as much problems as we all seem to have with them, surely there would be crowds proclaiming their virtues?

Putting it in the fuel I don’t think will hurt though, but I think it says run it through a tank full and then change your oil? Theory is it will clean out the carbon and a lot of that will be flushed down in the pan.

[Craig Cape Town]

I use seafoam in the fuel (petrol/gas) of my 4 stroke mercury 3.5hp dinghy motor.
Small motors have really small jets and it helps keep them clean, especially if the motor stands for a week or more. If the fuel in the carb. dries it can leave a residue, called varnishing, which can restrict the flow of fuel.
Only a small amount is added to the fuel (about a tot per gallon), so the can goes a long way.
I don't see the benefit of adding it to oil and have not of heard of anyone doing so.
Small 4 strokes are so temperamental. I miss my old 2 stroke die hard seagull.

[thinwater]

This is one of many additives lab and field tested by Practical Sailor Magazine. It does some positive things in gasoline. As for oil... I wouldn't touch that on a bet. As A64 said, regular oil changes prevent the problem.



https://www.practical-sailor.com/sys...-vs-gum-sludge


I used to think all parts store additives were snake oil. I now recognize several as being helpful. However, some are still snake oil and some can actually make things worse. But Seafoam is a good one with a good track record.


(chemical engineer in the fuel business)

[Lake-Effect]

I like SeaFoam as something to add to the first tank of the season, to help clean up the outboard's carb. I also like to use it when trying to fix some new-to-me problem motor (like the gas lawnmower I found abandoned curbside, now my regular machine)

It also functions as a gas stabilizer, though it's more expensive than dedicated stabilizer.

I would NEVER add SeaFoam to oil, except as something to thin the oil prior to a brief engine run to mix and warm up, then an oil-change... but again there are cheaper oil flush products.

So - I keep SeaFoam around as a cleaning additive to gas, with bonus stabilizing properties.

[Pete17C]

I've never used sea-foam, so I don't know, but if it requires you to shake it before use, I would avoid it.

Was told by a mechanical engineer, if you have to shake it, it means some part of it will settle out. That's not a good thing in your gas tank.

[thinwater]

Originally Posted by Pete17C

...Was told by a mechanical engineer, if you have to shake it, it means some part of it will settle out. That's not a good thing in your gas tank.

That was a mechanical engineer. You needed a chemical engineer.

Some of the additives can crystallize out of solution in extreme cold weather when stored as concentrate in the can. But like sugar dissolves in water, they will dissolve in gasoline in seconds. In fact, many additives used to formulate oils, fuels, and even antifreeze, must be protected from freezing temperatures when in concentrate form. I ran a large antifreeze blending operation, and all of the chemical concentrates had to be kept in heated rooms.

But I have never seen sediment in Seafoam. I believe it is a generic precaution. I've spent years testing these sorts of products. No, I did not work for Seafoam.

[Pegu Club]

We use sea foam in the gasoline for our Honda 2.3 outboard dinghy engine to help keep the carb clean, we also never put ethanol gas in our outboard, that stuff will make you want to row your dinghy...

Fair winds,

[a64pilot]

Originally Posted by thinwater

This is one of many additives lab and field tested by Practical Sailor Magazine. It does some positive things in gasoline. As for oil... I wouldn't touch that on a bet. As A64 said, regular oil changes prevent the problem.



https://www.practical-sailor.com/sys...-vs-gum-sludge


I used to think all parts store additives were snake oil. I now recognize several as being helpful. However, some are still snake oil and some can actually make things worse. But Seafoam is a good one with a good track record.


(chemical engineer in the fuel business)

30 years or so ago I had a JD 310 backhoe, it would idle on two cylinders and would only run on three once the RPM picked up, its injectors were bad, real bad, I bought it like that and think it was why I got a good deal on it.
I was saying something to the local Chevron Jobber when I was picking up some fuel. He gave me a bottle of what is called Techron. I tired it, figured I had nothing to lose, and it honestly cleaned up those injectors and it ran fine, took awhile though maybe 5 hours of running and it wasn’t an instant fix.
I still had the injectors overhauled, one or two needed shimming and I think a tip or two needed replacing, but the Techron really did work.
I figure major companies like Chevron and Shell etc are less likely to sell snake oil.
I used to believe Marvel Mystery oil was snake oil, just some mineral spirits and something to make it smell good, But since then I have seen more than one R1340 P&W engine that will stick valves if it’s not in the oil, so it does something, even if it is just mineral spirits and peppermint oil or whatever.

[Stu Jackson]

Have you considered reading the label?

[Ghostrider421]

SeaFoam is ok for small outboards.
Techron for larger engines - gas and all size diesels.
Standyne, Power Service and Howes for diesels - REMOVES WATER
NEVER PUT INTO OIL

[thinwater]

Originally Posted by a64pilot

...He gave me a bottle of what is called Techron. I tired it, figured I had nothing to lose, and it honestly cleaned up those injectors and it ran fine, took awhile though maybe 5 hours of running and it wasn’t an instant fix.
I still had the injectors overhauled, one or two needed shimming and I think a tip or two needed replacing, but the Techron really did work.
I figure major companies like Chevron and Shell etc are less likely to sell snake oil....

Yes, Techron is the real deal. It is one of those that I tested.

[n5ama]

Originally Posted by Stu Jackson

Have you considered reading the label?

Yes, I not only considered reading the label, I read the label.

I’m 73 years old and have had some positive and some negative experience with “labels” relative to reality.😁☹️

The label says this product cleans fuel components, stabilizes fuel, cleans deposits, lubes upper cylinders, de-ice and anti-gel and works on any kind of fuel; gasoline, ethanol blends, diesel, biodiesel blends etc. Everything but NUCLEAR energy.😳

Ok, I read the label but now I want reality and I think through the many helpful replies, I now have a great dose of reality.

Thanks!!

PS; The label also states that this product removes harmful oil residues when added to the crankcase. Is this a case of half the ad being accurate and the rest being snake oil?

[mvweebles]

There's a YouTube guy ("Project Farm") who does all sorts of testing. Here's one for SeaFoam vs Marvel Mystery Oil. If you go to his YT Channel and search "Seafoam" you will find several interesting experiments. In general, he's fairly positive on Seafoam. Interesting channel for DIY mechanic types. He blows-up a lot of small engines.

https://www.youtube.com/watch?v=J3F3jDa2xhg

[n5ama]

Very interesting comparison between the three biggies. It seems all of them are at least somewhat effective. I've actually used the Marvel product to free up the rings on a 100 year old hit-or-miss engine. Of course I've done the same with automatic transmission fluid (something I would never attempt on a modern engine).

I'm inclined to try a can or two in the fuel on my Tohatsu. I'm not inclined to do this for very long because its an ounce/gallon of fuel and I paid $8 for 16oz. I'll be in the Gulf's ICW this next week and if the current little storm gets to be more of a threat on the Texas Gulf coast, I'll gamble on the first 30 gallons of treated fuel as insurance.

I appreciate the input.