I’m finishing up restoring a 2004 Sportsman 500. It runs great once warmed up, but compared to my other 3 similar Polaris ATVs, it seems sort of “cold blooded”, meaning it doesn’t start without choke when cold (the others all fire right up on all but the coldest mornings without choke), and it takes quite a long time running on various amounts of choke to warm up to running temperate so it doesn’t bog. Again, once warm, it runs great, spark plug looks great once removed, will run strong and idle forever once warm. I went through the carb and cleaned it thoroughly during the restore. All parts looked fine, it wasn’t even very dirty when I did it. The only thing different about this one is that the fuel/air mixture screw plug was still in the carb, so I left it in, which means I haven’t adjusted fuel/air away from factory settings. I believe this is the original Mikuni carb that came with the machine. Would the factory fuel/air setting cause this? Should I get the plug out and adjust the fuel/air mixture?