I have a 2005 scrambler 500 HO. Riding it last winter with friends it died on me and would only crank over unless the key and kill switch were tuned off then back on and then would start fine. This happened about a dozen times getting back to the truck. Now it sometimes wont start at all and others times start fine.

 

Coil???? thats my guess.

 

ignition switch id say

 

mine does that when it gets wet. sometimes i cant get it to turn off.

 

my buddy has a 500 scrambler, did the same thing, would crank over, catch idle then die, sounded like fuel issue but, once it died u would have to shut the key and kill switch off then back on so it would fire it up, we were baffled, after trial and error turned out it was the BATTERY, new one and it fired right up, turns out the computer module on these bikes need a good battery, I THINK..... dont know for sure...
this sounds just like my buddies bikes symptoms, happened randomly out in a field, had to restart it many times on the way home then eventually wouldnt do anythignexcept idle hope this helps

 

Thanks for everybodies help and comments. I think I figured it out, I'm kind of embaressed to admit it but it turned out to be loose battery connections. I tightened them up and went for a good long ride with no problems