Lean for TAXI - how much? Piston Duke, other pistons.

KRoy7

Scope of Q would include other BS aircraft (Bonanza, etc.). Lean for taxi to avoid fouling. How to determine how much to lean for taxi?

Kirk

Black Square

This is an excellent question that is often asked in the real world too. Since the engine does not give any indication of accumulated deposits until they are significant, there is no way to determine what is the correct amount. I could go on in detail about what happens if you lean too much, or too little, but for the sake of this question, I think I will just answer "about half way".

I can confirm that this will serve you well in almost any aircraft you fly in the real world, and also with the code in all my aircraft. Just like in the real world, if you forget to go full rich before advancing the throttles to full for takeoff, you might get a backfire as a friendly reminder to push the mixture levers forward.

KRoy7

Ok, got it! Thank you.

Spurious

I go for about half way too. You can hear misfiring if you lean too much, so not that far!

yawstring

From memory (standard disclaimers: only for simulator use, I won't be liable, I'm not a flight instructor, etc.), the Cessna 172S POH says to lean for ground operations by setting 1200 RPM, then leaning for max RPM. In practice, you can lean somewhat further, and at some point you know from experience about how far you need to pull the mixture knob out.