Posted for "Mark Steitle" <msteitle@gmail.com>:

Mike,

What do the snowmobile guys do about the oil in the gas issue? I would
guess that they have injection pumps, so it probably isn't an issue. My efi
system returns a significant amount of fuel to the tank it is drawing from.
I believe that running the electric fuel pump for 30 seconds to a minute
before starting on a cold morning, or after sitting for long periods, would
provide adequate mixing. I haven't heard of any of the RX-8 Mazda's having
any problem with this, but then they draw their oil from the engine sump. I
didn't want to do that because regular engine oil doesn't burn as cleanly as
2-stroke oil does. Also, I wanted to run Mobil 1 synthetic and that leaves
a gummy residue if injected and that will gum up the seals. This would
require a teardown. So, pre-mix it is.

It rarely gets below 40* in Texas. ;-)

Mark S.


[Data points.... about 10 hours have passed now and the 10dF gas/oil solution is still just that... it exhibits no stratification of any sort.   The other bottle that started out stratified is almost completely diffused, ambient temp (hi 80's), about 5hours later.  Initial (and guarded) conclusions... first, mixing 2-stroke oil with gasoline creates a solution which doesn't precipitate out at (typically encountered) below-freezing temperatures, and second, failure to agitate the mixture has no effect on the components' tendencies toward creating a solution on their own through normal diffusion, given enough time.  Personally, I'm not surprised.  The air we breathe is a solution and the only time we see any of its components separate themselves out is when the temperature and humidity levels reach the point where water vapor removes itself via precipitation.  It could be that we might be able to force the oil to precipitate out of the gas/oil mixture if we lower the temperature far enough, but I'm not willing to do a test using dry ice to get the mixture down into the -60 or -70 range.  Sorry about that <g>.   Besides, if it's -60 outside not only am I not going flying, I'm not leaving the house nor my electric blankie.  <Marv>   ]