I have a 2008 Polaris Sportsman 500 EFI.
When trying to start it, it just clicks.
I have used a jump starter to make sure I have plenty of juice, still just clicks.
I replaced the solenoid, same thing.
But when I utilize a jumper across the two poles of the solenoid, the atv starts and runs.
I cant figure out what is going on....any help is appreciated.

 

Starters can get intermittent when the brushes are worn. To be certain of the fault, put a high wattage 12v test lamp between the starter live lead and earth. Press start button, if solenoid clicks but lamp doesn't light faulty solenoid, if solenoid clicks and lamp does light nice and bright, but starter doesn't turn, faulty starter. Battery must be well charged before doing the test and be sure it is that solenoid clicking. Some bikes have two starter solenoids (Kawasaki KLFs do) I don't know Polaris well enough to say.