Originally Posted by helicopter-redeye
You could get more range also by fitting an EGT lean-o-meter and lean to max plus fly higher. [snip]...(but the PoH does not recommend leaning)
h-r,
The wording in the POH is actually a bit stronger than 'not recommended':
From a RavenII POH, page 7-9, under Systems Description, Engine Controls (page date 3 Oct 2002) it states:
CAUTION In-flight leaning with engine mixture control is not allowed. Mixture must be full rich during flight.
It might well be different for the carburetted versions though.
HTH,
B73