Hi Remi,
It is quite possible that I got the front and rear mixtures mixed up. I
will check my notes when I get home tonight to see if this is the case.
The point I was trying to make was that;
1) the intake manifold does not feed all cylinders symmetrically,
causing some to be leaner than others,
2) The evidence suggests that on our 912S, the lean cylinders start out
lean of peak at see level.
We believe this lean of peak is acceptable because the heads are liquid
cooled.
regards,
Terry
________________________________
From: owner-europa-list-server@matronics.com
[mailto:owner-europa-list-server@matronics.com] On Behalf Of Remi
Guerner
Sent: Monday, January 19, 2009 12:50 PM
Subject: Europa-List: Mixture control
Terry,
I am coming back to this subject as I am doing some maintenance on the
engine and had to remove the exhaust system. I took this opportunity to
look at the coloration inside the exhaust elbows. Here is what I found:
Cyl 1: black
Cyl 4: white
Cyl 2 and 3: light brown
So cyl 4 is the leanest on my engine. Cyl 1 is the richest and the other
2 are in between. My engine has 350 hours and no adjustment of the carb
needles were done since new. I could adjust the right carb needle to run
leaner on Cyl 1 and 3, but the two front cylinders (1 and 2) would still
run richer than the rear ones. This is different from what you
experienced with your own engine. Mixture maldistribution is obvious
here and does not seem to be repeatable on all engines of the type (912
ULS).
Regards
Remi Guerner
F-PGKL
>>>>>>>Testing has shown that the standard rotax carb settings are
actually lean-of-peak at sea level on the front two cylinders <<<<<<<<
Terry Seaver
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