Anderson Ed wrote:

Hi Jim,
 Good to hear from you.  Sounds like your mixture may be a little rich
to me.  I had black soot on my plugs before I discovered my mixture was
over rich in the high >5500 rpm range.  Had so much fuel in the mixture
above 5500 rpm that my EGT was lower at 5500 rpm than at 4500 rpm.
After retuning injector timing, I could then detect a change in EGT, RPM
and sound when engine was leaned by mixture control. Plugs now have a
light grey/tan color veres black.  Althought after seeing my plugs
condition, I figure I might had run it overly lean or the plugs were
simply not "cold" enough for the engine in that tune condition.  Plugs I
had attempted to use were specified for "City driving" by MazdaTrix and
I suspect that long duration high RPM running simply was too hot for
them.

Regarding the 4 oz to 12 gallons.  I would not take issue with Tracy's
recommendation, however Pettit Racing (Mazda engines for Racing) has the
Proteck-R brand of two cycle oil which they claim is specially
formulated for turbo Mazda engines (see www.PettitRacing.com).  They
recommend 4 oz to 12 gallons.  Since I have no knowledge of its specs vs
other two cycle oil I can only assume that since they build and race
Mazda engines they know of what they speak. I use it primarily because I
can carry less when flying away from home base.  If I were caught
without it and had to use a different two cycle oil I would follow
Tracy's recommendations as his 800 hrs on his engine has something going
for his views.

Guess I should send a few Ozs to Paul and let him do his heat test.

Ed Anderson

 
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