I've found that when I pull the throttle all the way back on my G that it shuts off. Researching the carb I've found that the primary idle passage doesn't get closed off so should the tractor still run with the throttle closed? I had this carb apart once and bought the #40 and #53 drills to clean out the passages. I ran small wire through the idle passages in the bore of the carb but maybe I didn't get them clean enough? Searching on here I came across a discussion on a DLTX 18 and a member by the name of "John Deere D" posted a bunch of pictures of a manual he bought that goes in depth in the cleaning of these carbs. Does anyone know where I can get one of these manuals?
http://www.yesterdaystractors.com/cgi-bin/viewit.cgi?bd=jd&th=551992
http://www.yesterdaystractors.com/cgi-bin/viewit.cgi?bd=jd&th=551992