Why does this 2004 polaris 500 sportsman not idle until it has warmed up what can be done to get it to idle?

if the air to fuel mixture, or the jets are not correct it will not idle until warmed up or not idle at all. or the choke could have something wrong with it. try cleaning the carb and adjusting the idle screw located on the side of the carburetor and if that isn't the problem then it might need re-jetted