I 2001 Polaris sportsman 500 ho was riding an hit a mudhole an it just shut off an wouldn't start back up an I've let it sit an an have tried two more times to start it an all it will do is turn over

 

Pull the electrical connections,blow out any moisture especially at the cdi and coil connections and use some electrical grease.If this doesn't help then pull the recoil housing as water may have entered. Blow out any water or moisture,best to use some electrical spray. Make sure the pickup coil face is clean along with the flywheel tab as that can keep one from running if muddy. If it still doesn't crank after that check the resistance on the pick up coil red and white/red wires that lead to the cdi. Should be around 75 ohms.

 

Did you validate spark????