Tracy, for what it’s worth, I also see the leaning of the mixture
at the staging point which happens to also coincide with the staging
“bog”.
I never knew what was causing the bog and
since I don’t fly there nor encounter if during flight, it’s never
really bothered other than wondering about what was causing it.
Once I had a screen display to watch the
bin pointer, the staging point and the air/fuel mixture on the same screen, all
at the same time, it became very clear that leaning of the mixture (or at least
that is the indication of air/fuel ratio indicator) is happening.
As my bin pointer moves from the hump at
the idle (low rpm) region, it jumps from the low rpm map to the high
power/manifold pressure chart above bin 64 – not staged yet. Still
no bog, but as it moves a few bins higher the air/fuel indicator
dives from rich side to off the bottom of the scale lean and the bog begins. At
this point my staging sign goes from 2 injectors to 4 injectors indicating that
the EC2 has signaled staging. It last for approx 3-5 bins (memory’s
a bit vague here) before the A/F indicator comes back up the scale. So
something is causing a lean condition. I always speculated that it had
something to do with the air/fuel mixture in the secondaries making the
transition from ”dry” to wet - but couldn’t quite convince
myself.
The only way I have been able to eliminate
the bog is to increase the richness of that region (3-4 bins) to approx 80-90
(out of 255) which is not really a rich setting, but it works and has eliminated
the bog. I enrich each bin’s bar watching the A/F indicator as soon
as it stops going completely off the lean end of the scale, I stop and that seems
to work for me.
Ed
Ed Anderson
Rv-6A N494BW Rotary Powered
Matthews, NC
eanderson@carolina.rr.com
http://www.andersonee.com
http://www.dmack.net/mazda/index.html
http://www.flyrotary.com/
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