It's sometimes called a throttle chop also. The gist of it is to determine what's going on mixture-wise at various throttle settings. One method is to mark your throttle openings on the grip at 1/4, 1/2, 3/4, full (small piece of tape for example). Warm the bike, then run at the given throttle opening you wish to check for some period constantly, say half mile, preferably under some load, such as a slight grade. Then pull the clutch and hold it in at the same time hit the kill switch. Do not let the clutch out until the bike is completely stopped. Pull over, pull your plugs and then check the deposits toward the tip of the center insulator and compare them to various charts that are available. Hope this helps.
