Doug wrote:

I think the main thing is to lean enough to get proper burn, but don't
lean so much as to burn things up. I have some friends with probes on
all cylinders and carbureted engines who have tried to run lean of peak
and they have mostly given up. Just doesn't work on carbureted engines.

If you said "most" carbed engines, I probably wouldn't quibble. However,
it does work on some. It certainly works on my Continental E-225 with a
Bendix PS-5C carb. Its harder to do, but can be done and does work. Here
is what I had to do:

1) overhauled my carb and had it flow tested to make sure its doing its
job.
2) Pull off the throttle back a bit less than one inch. This put the carb
out of the enrichment mode that it is with full throttle. I think it may
also put a bit of turbulence into the airflow that helps the fuel
vaporization.
3) If I can't get smooth LOP operations with the above, I'll play a bit
with carb heat (which is actually alternate air on my plane). Causing the
induction air to be a few degrees warmer will often help get the
vaporization (and hence good distribution) needed.

I believe I've heard the GAMI folks say that getting good distribution is
easiest on the large Continentals. Something to do with the way
the stock induction is done.

--
Frank Stutzman
Bonanza N494B "Hula Girl"
Hood River, OR