Just received the email below from out local FAAST Team representative concerning ground operations.
"During the discussion a couple of operating habits came to light..... Leaning on taxiing out for takeoff : a carbureted engine has a fixed idle jet. That means a fixed amount of fuel goes to the engine. If you are below 1400 rpm the mixture control does nothing. You should be below 1400 RPM taxiing. Fuel not only cools but lubricates. Unless there is specific information in the POH/AFM that tells you to lean on the ground...it is not a good technique!
The last issue is plug fouling. This is fairly rare yet I hear about it all the time. Clearing a plug should be done at no higher than run-up RPM and should only occur for less than 30 seconds. Repeated plug fouling or lack of clearing per the manufacturers recommendations means you have a mechanical problem. Get an AMT to look at it. It might be the wrong plug, too cold of a plug, poor timing, etc.
YOU ONLY HAVE ONE ENGINE AND YOUR LIFE DEPENDS ON YOUR KNOWLEDGE OF HOW TO CARE FOR IT. "
At our club we insist that our members lean during taxi - I am a little surprised that they are also suggesting that the idle jet is set to 1400 rpm. Should this not be set to 600 -650 rpm ? Since this is from a source of some authority just wanted to check if I'm missing something ?