The 2020 YZ65 is the smallest-displacement MX bike that Yamaha currently offers so you can start your kids at a non-intimidating 65cc and grow from there. 

The two-stroke engine is also easy to learn maintenance on if you're a hands-on sort of person and want to teach your kids to be that way as well. Like the slightly larger-displacement YZ 85, it features the YPVS Yamaha power valve system to provide smooth, even power across the rev range, making it super user-friendly for kids to learn on. 

KYB forks and KYB rear shock are fully adjustable for compression and rebound, and you can scoop one up from your local Yammie dealer this month in Team Yamaha Blue for a cool $4,599 MSRP.