Sounds like some one took the cheap way out. The black kill wire from the cdi also ties into the left control switch and the ignition switch kill circuits. The problem could be in either of those,left control switches were really bad on this,or the black kill wire from the cdi has shorted out internally and the po was too cheap to get a new one.Just toggled it instead.If you want to fix it right go through the ignition checks and wiring diagram in the manual to help track down where the problem is.2002 Polaris Sportsman 500 Service Manual PDF Download

 

It doesn't have a start button it's all in the key switch. I do have a service manual and I will start with that thanks for your advice.