Remi Guerner wrote:
> 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
Remi
the inlet to the carbs can have a marked effect. Some friends were
struggling with a Jab6 installation, single Bing carb, the rear
cylinders were overheating. After many fruitless efforts with cooling
baffles over a frustrating year, the cure was to replace the nice smooth
elbow at the inlet with a square box. Courtesy of Tony Higgins experience.
Graham
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