I have an underused '06 Mule 610 with 275 hours on it that has been sitting too much. It starts just fine and idles with no missing or stalling but, when I try to accelerate, even with no load on level ground, it stumbles and won't go unless I use the choke. I haven't tried to take it out for a run because I'm not sure it will come home under it's own power but it does seem to run OK with the choke fully closed. I changed the fuel filter and checked the air filter but nothing else yet.