Success! The two small grandkids rode the minibike today. We began with them rolling it downhill with no motor, next we started it on flat ground. The cheapo brake lever keeps loosening from the handlebar, and they are used to a quad with a thumb throttle but all in all it's a success.
Both were a little overwhelmed and found it difficult to turn, so do I. I got them on the Honda XR70R, they didn't ride it but they are nearly as close to touching the ground on it. Next spring for sure.