dead battery
are you checking for spark while turning over the starter at the same time?
does it have a pull cord?
when the battery is low the starter motor takes most of the power from the battery and there's not enough of leftover power for the coil
there is a way to bypass that, but im afraid to tell you how to do it cause if you do it wrong you can smoke the whole electrical system, just give the battery a good-long charge with a charger of 4 amps or less, then try it again
have you ever thought of that?
oh yea, one more thing, the battery can be bad even if it is a new atv, I know many dealers that take the new battery outta a new atv and sell it and replace it with a junk battery cause they know batteries are not covered under warranty,,, yea they do that all the time