When learning i was tought the old wives tale dont lean til over 3000 and by the way just forget it anyway you've got more important things to worry about!
I didnt know what the red knob did for years i suspect like most.
Then bought into an old cherokee 180 which fouled its bottom plugs if you didn't lean.So started to learn a bit.
biggest learning curve was when i sat behind an IO540 which has a fuel flow. Properly leaned out the difference is 24gph full rich in a nominal 65% cruise as opposed to 12.5gph makes a hell of a difference.
Read Deakin he explains it all. following his advice i just had a EDM 700 fitted what a wonderful toy!
Someone was worrying about detonation in the context of running near peak egt at 75% power at altitude, if you look at most poh's you cannot get 75% power at any setting at that sort of altitude with a normally aspirated or injected engine. i cannot get near 75% at 8K.
certainly my poh expressly forbids lean of peak opperation and so do most folks advise agains trying to unless you also have gamijectors. I have for short periods set lop and it seems to work much cooler engine with little power loss.
Anyone got an opinion on lop running and gami's????