I doubt the noise level exceeds any ordinance unless the ATV is modified.

I empathize with your situation but you are being bitter and controlling. Let the kid have fun on weekends, you can't control the outdoors and people are well within their rights to make noise during the day.

Move to a gated community or buy land in the middle of nowhere for the extent of control you're looking for. Play some music, go outside, watch TV, literally anything for the few hours a weekend that kid rides around. Or watch through your blinds and get angry.