David Megginson wrote in message ...
Chris Kennedy writes:


Up here in the mountains we lean to the point of stumbling and try not
to reduce RPMs below 1200 on our O-540 (as does the local FBO with its
O-360). Except on very cold winter days we lean for departure as
well.

As far as I understand, carbureted engines have a separate idle
mixture control that needs to be adjusted with a screwdriver on the
carburetor itself (i.e. on the ground, by an A&P). If that is set too
rich, you can lean during ground idle until the cows come home and
still end up with fouled plugs.

From Chris's description, he's leaning to just above idle cutoff.
That will do the trick no matter how your idle mixture is set. On my
O-360, the mixture control is just above idle cutoff and the most rpms
I can make are about 1200. Leaning that aggresively guarantees that
you will not take off without enrichening the mixture.

John Galban=====N4BQ (PA28-180)