I've heard from many car people that premix works very
   well without worry about the oil settling out of the
   fuel.  I don't know how often they were driving the
   cars, though, which could be a factor.  Clearly, if
   you're autocrossing the car every weekend, it'll mix
   the oil up nicely after just a few corners.  I haven't
   heard anyone talk about having premature engine
   trouble because of premix.

   On the other side of the coin, I've seen countless
   dirtbike engines that had seized pistons and a handful
   of oil-fouled spark plugs from the last ride.  They'd
   poured premix into the tank and then let the bike sit
   for several weeks, and the oil settled out.  They were
   running way too much oil off the bottom of the tank
   (thus the fouled plugs) and once they got through the
   oil, it ran like a raped ape...  for about 5 minutes,
   until it seized due to lack of lubrication.

   If it was me, I might adapt the Mazda oil metering
   pump to draw from a reservoir of two-stroke oil rather
   than the crankcase.  Then you get the cleaner burn of
   two-stroke and don't have to worry about depleting the
   oil supply in the crankcase; also, you don't have to
   worry about oil settling out of the fuel (I don't know
   if it happens enough to be a problem, but it's easy
   enough to eliminate any worries about it by using the OMP).

   Adam Wade


   The next message should be interesting :)

   Paul Lamar ...No rotor no motor

Adam,
I'm not sure if Paul was anticipating a reply form Me or had another
post to which he was refering. As an FYI though, I'm a long time
motorcyclist and constructor. I have done 2-stroke engine work for
Kenny Roberts. I worked for Kawasaki in the 70's. What I was refering
to, and I believe was confirmed by the fact that they are adding bio-diesel
to the Ethanol is that there is a lubricity problem. I have worked on
several
2-cycle kart engines running METHANOL, which though originally drawn
from a petroleum stock has trouble with oil separation and works best
with some of the castor-based oils, or current synthetics designed for
alchohol fuels. I have considerable experience, but not with Ethanol. If we
do have a chemist monitioring the list perhaps he or she can provide us
with non anecdotal information as to wether oil will stay in solution in
ethanol. Doug, I don't think you could forgo the mix oil just because there
is bio-diesel in the mix either. The bio-diesel probably only brings the
lubricity back near to that of gasoline. I'm not trying to knock E85 but
with any new addition or change we must cover all possibilities. For
operation in a piston engine with best power we would raise the
compression ratio at least 2 points when running on methanol. Typically
the ratio would be around 14:1, gasoline gets close to compression ignition
that high, so the setup for the different fuels would vary a lot.
Bill Jepson



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