I thought that if you did a speed pass to clean it out that if it was too rich then it would high idle for a few seconds then drop, but for a properly tuned engine it should not change idles after you clean it out. This is in the Jarod Tebo video as well as in the engine tuning guide in this forum. Most people seem to have the HSN too lean and the LSN too rich which shortens the life of the engine because on the high end it is too lean but people don't notice because of the extra fuel in the crankcase from a rich LSN.