2-stroke oil

[Saskgreen]

Hello everyone. Have a oil question, which can open a can of worms I know. I have a 25hp Johnson that calls for 50:1. Just wondering what you guys run for oil? Looking for something with minimal smoke and good protection. If you've been using a certain one for years, and easily to purchase I'd like to know! Thanks for your time.

[catnthehat]

I run Amzoil in everything, have for over about 20 years
Cat

[dodgeboy1979]

i used to use the shell nautilus from canadian tire in my old Johnson. It didn't smoke much and you can often get it on sale.

[JohninAB]

i used to use the shell nautilus from canadian tire in my old Johnson. It didn't smoke much and you can often get it on sale.

X2

[Salavee]

As long as it's specified TCW-3 you are good to go.

[Tom Pullings]

i used to use the shell nautilus from canadian tire in my old Johnson. It didn't smoke much and you can often get it on sale.



X3

Also the mystic outboard is good and can be found quite cheap.

I find that pretty well all 2 stroke oil is pretty good now. It’s just a matter of finding one that has a tolerable smell. A few of the high dollar synthetic oils make me sick after a couple hours.


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[AndrewM]

I run Amzoil in everything, have for over about 20 years
Cat

Do you go 100:1 as it recommends in everything?

[TROLLER]

i run amzoil in everything, have for over about 20 years
cat

like he says amsoil

[catnthehat]

Do you go 100:1 as it recommends in everything?

Yup!:)
Cat

[Salavee]

Just a little tidbit for those who use a particular oil for both 2- stroke dirt bikes and 2-stroke outboards. The specs differ due the flash point of the oil.
A 2-stroke O/B runs significantly cooler cyl head temps than a two stroke dirt bike due to the continuous flow of cold water thru the jacket. They require an oil with a lower flash point. Dirt bikes,whether liquid or air cooled. operate at combustion temps considerably higher and therefore require oils with a higher flash point. If it is meant for O/B use it will state it on the container. If it was meant for Dirt bike use it will state that also. If it says good for both
I would leave it on the shelf

[Redneck Tommy]

i used to use the shell nautilus from canadian tire in my old Johnson. It didn't smoke much and you can often get it on sale.

X4 but I use any TC-w3 without any worries

[Saskgreen]

Thanks for responses, picked up some of the Shell Nautilus from Canadian Tire today. :happy0180:

Will watch for it to come on sale next time!

[pikeman06]

You are good to go with the nautilus. I mix 50 to one at the very leanest. If I gotta buy a sparkplug then fine but 100 to one in a tank mix is asking for a melt down. If it sits for too long and separates or isn't agitated proper to begin with you could lean out and scorch your junk. I mix 50 to one in the tank plus the injection for my first tank of the year in case the injection fails. Better safe than sorry, but I got a bunch of old yamaha 2 stroke enduros in my collection and finding parts aren't so easy but the rich mix just makes smoke not headaches.

[Saskgreen]

Says right in my manual 50:1. With my boat tank being 25L to achieve the proper ratio should add 0.5L of oil. Good thing to keep it simple lol

[old dog]

When I had a two stroke I used shell nautilus as well. Never had any issues

[AndrewM]

You are good to go with the nautilus. I mix 50 to one at the very leanest. If I gotta buy a sparkplug then fine but 100 to one in a tank mix is asking for a melt down. If it sits for too long and separates or isn't agitated proper to begin with you could lean out and scorch your junk. I mix 50 to one in the tank plus the injection for my first tank of the year in case the injection fails. Better safe than sorry, but I got a bunch of old yamaha 2 stroke enduros in my collection and finding parts aren't so easy but the rich mix just makes smoke not headaches.

Tonnes of info on the Amsoil at 100:1 with zero issues and more power. Manufacturers have to design for the worst quality oil.

[Tigger72]

OPTI-2 I put this S@$T in every two stroke I've owned... ZERO issues

[pikeman06]

Tonnes of info on the Amsoil at 100:1 with zero issues and more power. Manufacturers have to design for the worst quality oil.

Excellent product no doubt about it. I'm just old school, especially the first run. I run my sleds a bit rich too. Like I said I got a bunch of vintage stuff I don't use much. The beauty of a 2 stroke is if it's a bit rich it will let you know and a 4 dollar sparkplug is better than tracking down engine components on a 40 year old machine.

[Tom Pullings]

Also richer oil fuel mix generally makes more power cause the extra oil helps with compression. Assuming both are jetted properly. I remember reading somewhere that 16:1 is pretty much the mix with the most power potential in 2 stroke motors.

[catnthehat]

Also richer oil fuel mix generally makes more power cause the extra oil helps with compression. Assuming both are jetted properly. I remember reading somewhere that 16:1 is pretty much the mix with the most power potential in 2 stroke motors.

My buddy and I had a discussion about that about 40 years ago
He argued 20:1 was best as opposed to 40:1
Three guys in the boat the 20:1 mix would barely plane it
40:1 had no problem getting on plane
Cat

[Tom Pullings]

My buddy and I had a discussion about that about 40 years ago

He argued 20:1 was best as opposed to 40:1

Three guys in the boat the 20:1 mix would barely plane it

40:1 had no problem getting on plane

Cat



Well you can’t just add more oil and expect it to run better. Or mix way leaner for that matter. You have to jet the carb accordingly to take advantage of the mix.


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[Tom Pullings]

https://www.off-road.com/dirtbike/tech/twostroke-fuel-ratios-premix-myth-vs-reality-54169.html

This is a decent explanation. For dirt bikes but the ideas are the same for all carbureted 2 strokes. I can’t find the Mercury tests with the ultra rich oil mixes I was talking about earlier.


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[catnthehat]

Well you can’t just add more oil and expect it to run better. Or mix way leaner for that matter. You have to jet the carb accordingly to take advantage of the mix.


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I have never had to reject an outboard, tweak the mixture screws sometimes is all .
On the new Sportjets we would run a tank of 50:1 premix along with the injector
Bag filled with Amzoil for break- in then rn straight Amzoil after that
Never ever fouled plugs either .
Cat

[AndrewM]

https://www.off-road.com/dirtbike/tech/twostroke-fuel-ratios-premix-myth-vs-reality-54169.html

This is a decent explanation. For dirt bikes but the ideas are the same for all carbureted 2 strokes. I can’t find the Mercury tests with the ultra rich oil mixes I was talking about earlier.


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I believe this is what you are referencing but doesn’t reveal the science behind it.


I was involved in an oil ratio test for Mercury Marine. We tested various oil ratios on a few different outboard engines that were commonly used in racing. We did not test every engine, as many engines were similar designs with different rated outputs (a common trick in outboards). We partly based our testing on some industry information by a chain saw and go kart engine company (Mcculloch).
In any case (for the most part) the oil used was Factory outboard oil. We did try other oils without much HP difference.

Oil ratio's covered the extreme range.

The bottom line is that more oil made more power. The standard 50 to 1 ratio was sufficient to provide lubrication without operational problems such as smoke and plug fouling. 32 to 1 made more power and 16 to 1 made even more power. We even tried ultra rich ratio's like 8 to 1 or 5 to 1 and power did improve to a point even at the extreme end of the test. 100 to 1 did show a significant loss of power. This was not designed to be an oil test to end all tests, just a way to determine how to make more power for certain racing classes,

While the test was not designed to indicate wear, I did draw some basic conclusions. In racing applications more oil reduced wear slightly. This is as you might expect. What we saw is that any normal oil ratio protects the engine well. Lean oil ratios seemed to work well until the temperature and stress got out of hand. That is where a lean ratio would not be enough for full protection.

I have since read that oil ratio's around 32 to 1 provide nearly all the protection that is available for most performance engines. My experience backs that up. Yes, there would seem to be some extreme examples of engines that need 16 to 1. I am not sure I can draw a conclusion as to which engines need this level of lubrication, but I would guess it would be well out of the norm, especially for dirt bike applications.

Another note on 2 stroke lubrication, upon teardown, any reasonable ratio will leave a significant amount of oil on internal engine parts. While many people think the oil just races through a 2 stroke engine, this really is not the case. It does separate from the gas and lubricate the bearings, con rod, and piston skirt in full force.

[Redneck Tommy]

I fly an ultralight aircraft with a 2 stoke engine and run 40-1 after suffering an engine failure before my tbo the engine life between overhauls it was only oiling at 70-1. 40-1 is also recommended by most aircraft engine builders and this is in an industry were every hour is trackef and record and engines with more oil last longer.

[AndrewM]

I fly an ultralight aircraft with a 2 stoke engine and run 40-1 after suffering an engine failure before my tbo the engine life between overhauls it was only oiling at 70-1. 40-1 is also recommended by most aircraft engine builders and this is in an industry were every hour is trackef and record and engines with more oil last longer.

What oil were you using when you had the failure? What do you use now?

[Okotok]

I run Maxima in my two stroke dirtbike because I like the smell of castor oil plus it's great oil.