Running too rich (too much fuel)
causes incomplete combustion resulting in spark plug fouling. Running
too lean (not enough fuel) causes overheating especially the exaust
valves.

I suspect most MSFS simulated aircraft do not simulate engine damage
from improper leaning. They will simulate the fan quitting at idle
cutoff though.

The most efficient way to determine the correct mixture is with a EGT
(Exaust Gas Temperature) gauge. As you turn the mixture control out the
EGT will increase to a point and then begin to decrease as the mixture
gets too lean.

In real airplanes there is a lag. Lean it out slowly. A Cessna 182
manual I remember reading said that it should take about two minutes to
find the peak. This may also not be adequately simulated in
"entertainment level" simulators.

Lean to peak RPM then turn it in a full turn.

I've never heard "a full turn", though I have heard the less helpful
phrase "a bit". Not all airplanes have vernier controls, and I don't
think MSFS aircraft do either.

Jose
--
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