Engine mixture guidelines

Mxsmanic wrote:
Up to now when flying in simulation, I've had the simulator take care
of engine mixture adjustments. However, since I'd have to do this
myself in real life, I've decided to make some modest attempts at
managing mixture myself. Unfortunately, the POH and the other sources
I've consulted are rather vague on how mixture should be adjusted.
Can anyone offer general guidelines on when to enrich or lean the
mixture? It seems that max rich is used when maximum power is
required (?), such as at take-off, but I'm not clear when the mixture
should be leaned in particular. And what are the potential
consequences of an incorrect mixture?

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As altitude increases the air gets thinner so you need less fuel to
maintain the proper air to fuel ratio. 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.
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. Lean the mixture until it peaks and then enrichen it
(turn it back in) until it drops 50°C.
Though not as accurate, you can also note a increase in RPM's as you
lean it. Lean to peak RPM then turn it in a full turn.
Remember FULL rich for takeoffs and landings unless your flying at
Leadville, CO or some other really high altitude airport.
Steve