I set mine up so it takes like 2-3 raps of the throttle to clean the motor out..... then start with the power jets wide open, make a pass, pull the plugs and look for heat marks on the metal part of the plug above the threads..... Do a search on alky plug reading there are a bunch of good threads on it.
http://www.dragstuff.com/techarticles/reading-alcohol-spark-plugs.html
http://www.planetsand.com/forums/ubbthreads.php/topics/654196/brown_colored_alky_plugs#Post654196
good link for ya... read up