ok guys I'm stumped ! my neighbor's '03 JD LA130, Kohler Command 23 horse Vtwin, 1300 hours, was parked for the last 3-3 1/2 years & about a month & a half ago I got it up & running again. When he parked it he did absolutely nothing other than to cover it up with a tarp. I changed the oil & filter, & the fuel filter, inspected the plugs,drained the old fuel & refilled it & replaced the battery. Started it up & it ran ok for a while then it started surging. I ran some carb cleaner through it & adjusted the idle mixture & it was ok again for a while. to make a long story short ... some days it runs beautifully & other days it will surge like crazy unless I run it with the choke half closed. I've run 2 bottles of gumout carb & fuel injector cleaner through it (about 1/4 bottle per tank of gas) changed the fuel filter a couple more times & still have the same problem. I even tried a different fuel pump from another tractor on it I've run it about 40 hours total now & wondering if anyone else has had the same problem. could there have been so much crap in the carb from sitting that I still have junk plugging the passages in the carb? I do know that my neighbor was starting this thing a couple times a year for a while, which probably only makes it worse, 'cause he never drained the carb & the fuel was just left to evaporate & I know for certain that he never put Stabil in it as he didn't even know what it was 'til I went shopping with him one day for some stuff for his mowing service. what do ya think? should I just pull the carb & rebuild it ?