Zach is just at the cusp right now I think. He's only 11, but he is tall for his age, and he is an only child, so he is very mature for his age.
It'll be interesting to see what he decides to do.
Tonight we ripped apart this 85KX that a friend of mine gave me. At first before we started, he didn't want to do it, cuz he is also a bit lazy, and wanted to build his Lego Technic's car he has been working on. But once we dove into it, he started to connect the dots and saw the similarities between the Lego cars he was building and the bolts he was unspinning on the KX.
It has a fried piston which he now has sitting on top of his dresser, and is proud to have removed from the bike himself.
So some major headway was made tonight in that respect.
After the teardown we visited a engine animation website that gave a really nice animation and theory behind a bunch of different piston engine designs going back to the 1700's (and a Wankel), and that really helped him solidify what he was looking at, and the things he just removed from the bike; carb, intake, exhaust, reeds, etc. So some learning was had there.
At the track this past Sunday we swapped bikes and I let him ride the XR200. It fits him pretty well I think, and am considering bringing it to the track for him when I get the YZ250 going. I think his XR100 is already too small for him, and was quite sluggish when I rode it. He is better than that.
So yeah, we have time, and he and I are both learning and having a great time, and I have stocked up on enough bikes to last us both through our transition periods. He even sat on my Shadow tonight and said "Dad, I could ride this..."
His feet touched the floor so...