Originally Posted by gtsum

Yes, if you richen the LSN, you will likely have to increase the idle accordingly. What I do (YMMV) is get the car up to temp and make high speed runs once the chassis is heat soaked...make sure your idle gap is around 1mm to start...get the hsn close, but not too lean..you want a good stream of smoke all the way to the top...when I bring it in to a stop, I listen to the idle....if it idles high and then drops to a lower idle within a few seconds (or a 2 stage idle drop), I lean the LSN....I do another high speed pass and repeat...once the idle remains constant (it might be high at this point), I am good...I will then adjust the idle speed to lower it down a bit. You might have to richen the hsn a bit after doing this. If your engine gets hotter the longer you run it, your lsn is likely too lean...this method works for me, but i will defer to Monty...lets see what he says!