rag
Active Member
Well, we have had low ceilings and miserable visibility for over a week now.... so time to over think all things aviation. This is a question I have been thinking about: It has been suggested and recommended by many much smarter than me to lean aggressively during idle (Lycoming type carbureted engines). I believe this is to reduce lead deposits? When I review the diagrams of the Marvel Schebler carbs, the mixture control metering sleeve controls the flow to the main jet and the idle jet circuits. Trying to control the mixture during idle is very difficult to do with any accuracy due to the very low fuel flow. It either kills the engine or it is so rich the idle circuit is controlling the flow - not the mixture control. My question is - why not set the idle mixture to the lean side (no RPM rise during idle cut off) and forgo trying to lean the idle mixture with the mixture control? I would think this would be more accurate and consistent, would allow full throttle control during taxi operations and one less item to forget when on the takeoff roll. Thoughts??? Forecast is for low ceilings for another 4 days.... maybe more dumb questions coming.....