Alot of things will affect firing. On/off switch,coil,spark plug,cdi unit,stator, and the ETC(electronic throttle control). When you say won't fire that means no spark from the spark plug correct? I would replace spark plug first. It could have fouled the plug.
2008 Dodge Caliper
2010 Chevrolet Equinox
2004 Honda ForemanES 400 4x4
(Currently I don't own a Polaris but I work on them all the time and get to ride cutomers for test rides. Maybe soon I will be a Polaris owner.)