the quad was working fine then the kids took out the key and it won't back so we fixed the keyswitch and it fits again. Now the check engine light is on and the engine won't turn. - battery is good- the key turns and the display is on and recognizes the machine in park or neutral- what could I try to get it started

 

If you have a check engine light, can you pull up a code? Other than that, maybe time for a dealer visit. I guess, today, not many folks spank their kids, but when I was a kid, If I monkied with something of my dad's, I would have had a bad time sitting, haha. You need to lock it in a shed/garage, away from kids. An 800 Outlander if far from a toy for kids to play with. BTW, my dad is 95 years old, I still don't monkey with his stuff, haha.

 

Lol well yea we let them ride it it was working just fine then after he took out the key and after 10 min tried to put the key back it stopped working this literally all went down in minutes while we were watching

 

Gotcha, heck, could be totally unrelated to the key, but couldn't hurt to remove the ignition switch, inspect for a loose wire or one that came off. Just for $hits and giggles, check the voltage at the battery. EFI and low voltage can give you fits. I know you said it's good, but it happens.