Any thoughts? Any opinions? Anyone know? I know leaning and acro do not exactly work together, at least not here in New England. Regardless one of the neat things about a Skybolt is that it makes a half decent cross country machine. Leaning now becomes a part of the flight regimen. I learned to lean by using a fuel flow meter in a Decathlon (prior owner instructions). I followed his method. It seemed to work well so I never questioned the procedure. Now with my Skybolt I would like to use the recently installed JPI Fuel flow meter and see that Lycoming, in their owner’s manual, mention this as a legitimate method of leaning. The problem is their tables are not exactly very clear regarding the procedure. In the Decathlon I simply leaned until the engine showed signs of running a little rough and then add 1/2 GPH to the rough running fuel consumption point. This is so simple compared to Lycoming unexplainable tables. What don’t I understand?

I am simply trying to come up with a method of safely leaning the engine at cruise and altitude. The EGT is not dependable. In the Decathlon I leaned the mixture till rough and then added ½ gal/hr of fuel. This seemed to work well but was it correct? Since Lycoming mentions that it is viable to lean by fuel flow I would like to know the method.  Lycoming does not explain nor are their charts very clear. I would assume every power setting at every altitude would require a different fuel flow to run at the correct air fuel mixture. I would also assume that the altitude I speak of is density altitude and not MSL. I believe this subject is a bit more complicated than most realize. First time pilots are taught to gradually pull mixture until the engine runs rough and then richen the mixture until the engine runs smooth or the RPM comes back to cruise power.  Add an EGT and you can now determine the peak EGT and if I am not mistaken drop the EGT by a specific amount. (50 deg)?  Now I am a little confused because if the best fuel air mixture is the same as the most efficient burning ratio is peak EGT the most efficient? I would think not since in many situations efficiency is measured by the delta T. All of the BTU’s going out the exhaust represent lost HP.  This all said and done my guess is I am missing some point that explains all of this and my main goal is to have a safe, easy and reliable method to lean using the fuel flow. I suppose the best method might be to lean to peak EGT, if mine worked reliably, and then add a little fuel to cool the cylinders.