Short term storage, empty carbs?

[boscoe99]

As Arte Johnson would say "Very Interesting"

I poured about a teaspoon full of premix into a small bowl made out of aluminum foil. It all looked to be just one liquid.

I then started blowing on the mix to try and evaporate the gasoline. Shortly after I started blowing small globules of oil began to appear. I blew some more and the small globules over time joined into one blob of two stroke oil. After a while the gasoline was gone and the oil remained.

I imagine this is what happens in a motor that uses premix. As the liquid gasoline/oil mix is being vaporized by the carburetor the oil precipitates out. The oil is carried on by the gaseous fuel/air mix and taken into the crank case. Just like if straight gasoline went through a carburetor and oil globules were thrown into the air stream just aft of the carburetor by an oil pump.

[99yam40]

I poured about a teaspoon full of premix into a small bowl made out of aluminum foil. It all looked to be just one liquid.

I then started blowing on the mix to try and evaporate the gasoline. Shortly after I started blowing small globules of oil began to appear. I blew some more and the small globules over time joined into one blob of two stroke oil. After a while the gasoline was gone and the oil remained.

I imagine this is what happens in a motor that uses premix. As the liquid gasoline/oil mix is being vaporized by the carburetor the oil precipitates out. The oil is carried on by the gaseous fuel/air mix and taken into the crank case. Just like if straight gasoline went through a carburetor and oil globules were thrown into the air stream just aft of the carburetor by an oil pump.

come on now , did you really do this yourself?
was it ethanol fuel? If it was you would have seem it get cloudy from the moisture it gathered.

I am curious about the high pressure oil delivery to the intake on oil injected motors you speak of.

I never though about it being high pressure, just a metered amount of oil sent to the motor.
is there a special nozzle on the end to spray the oil?

[boscoe99]

come on now , did you really do this yourself?
was it ethanol fuel? It was whatever gasoline that I had for my chain saw. Probably ethanol. Maybe I need to redo my test to see if those globules are water. If it was you would have seem it get cloudy from the moisture it gathered. Yep, really did it myself. Took all of about five minutes. Try it and let me know what you observe. The liquid looked a bit frosty (cloudy) while I was blowing on it.

I am curious about the high pressure oil delivery to the intake on oil injected motors you speak of. High pressure as maybe one psi? Maybe less. I don't know what the pressure output from the oil pump is. Would not be much I don't think.

I never though about it being high pressure, just a metered amount of oil sent to the motor. You got to have pressure to have flow.
is there a special nozzle on the end to spray the oil? Don't know. Don't think so.

As noted above maybe what I was seeing was water droplets and not oil droplets. Maybe the oil vaporized along with the gasoline. How does vaporized oil lubricate parts?

All I know is that running a two stroke on premix works. Works well. Had a Mercury two stroke over 30 years and never had a problem. I was just assuming (yes, I know) that if the gasoline turns into vapor in the carburetor (motors don't run on liquid gasoline) the oil must remain to get into and lubricate the motor.

Like I said, I am thinking about the dynamics of it all. Don't have a good understanding yet. Certainly I won't argue that it works in one way if someone says it works in a different way. Supposedly a bumble bee can't fly. I see them doing it all the time when they fly in to chew a hole in my deck. I won't argue that argument either.

[99yam40]

the oil and gas mix that is in carb bowl gets sticky as the fuel evaporates, ends up like a tar in the bottom of the bowls after sitting for a long time.

Seems oil by itself would not do that, but I never tried to set some oil out to see what it looked or felt like after months of sitting in the open

I have to think by combining the two it combines some of the molecules and some of the oil properties disapate or evaporate off with the fuel

[boscoe99]

Still contemplating my navel on a premix fuel/oil mix lubricating an outboard motor. How the oil gets from the liquid gasoline after the gasoline has been vaporized. How that oil then lubricates the motor.

A C60 runs on about .6 gallons per hour at 1000 RPM. 76.8 ounces of gasoline per hour. One 50th of 76.8 is 1.536 ounces in oil that gets added to the premix.

http://yamahaoutboards.com/sites/def...0144-XPR-Z.pdf

Now imagine that oil being divvied up between three pistons with piston rings sliding up and down their cylinders 60,000 times during an hour. All the while being lubricated on one and one half ounces of oil.

And the piston rings don't get all of the lubrication. Some goes to roller bearings on the crank shaft and connecting rods. Some gets blown out the exhaust. It is a wonder that two strokes survive at all. But they do.

[robert graham]

My 1999 C90 is premix and I've found it very easy(5 minutes) to drain each carb before any lay-up period just to be sure about any water or debris....this is an easy preventive maintenance item to ensure trouble-free operation. Same time I fog the cylinders....no problems so far!

[pstephens46]

Still contemplating my navel on a premix fuel/oil mix lubricating an outboard motor. How the oil gets from the liquid gasoline after the gasoline has been vaporized. How that oil then lubricates the motor.

A C60 runs on about .6 gallons per hour at 1000 RPM. 76.8 ounces of gasoline per hour. One 50th of 76.8 is 1.536 ounces in oil that gets added to the premix.

http://yamahaoutboards.com/sites/def...0144-XPR-Z.pdf

Now imagine that oil being divvied up between three pistons with piston rings sliding up and down their cylinders 60,000 times during an hour. All the while being lubricated on one and one half ounces of oil.

And the piston rings don't get all of the lubrication. Some goes to roller bearings on the crank shaft and connecting rods. Some gets blown out the exhaust. It is a wonder that two strokes survive at all. But they do.

Even more amazing that the new 2 strokes survive with the EPA requirements.

[scofflaw]

Still contemplating my navel on a premix fuel/oil mix lubricating an outboard motor. How the oil gets from the liquid gasoline after the gasoline has been vaporized. How that oil then lubricates the motor.

A C60 runs on about .6 gallons per hour at 1000 RPM. 76.8 ounces of gasoline per hour. One 50th of 76.8 is 1.536 ounces in oil that gets added to the premix.

http://yamahaoutboards.com/sites/def...0144-XPR-Z.pdf

Now imagine that oil being divvied up between three pistons with piston rings sliding up and down their cylinders 60,000 times during an hour. All the while being lubricated on one and one half ounces of oil.

And the piston rings don't get all of the lubrication. Some goes to roller bearings on the crank shaft and connecting rods. Some gets blown out the exhaust. It is a wonder that two strokes survive at all. But they do.

Fred Flintstone design. Nothing gets vaporized. Oil and gas enter the lower end of the motor as a liquid thru the carbs, oil coats the parts. Liquid gas finally enters the combustion chamber, Poof..combustion. Thee end.