I have a thought...^^^^^^^^^ my last reply.
Let that guide you.
Sounds like the 125 may be perfect.

 

Can't quite remember how big the Bombardier 90 is but the Yam Grizzly 125 is a Breeze with different plastics, and the Breeze is roughly the size of, and slightly down on performance of, the Suzuki LT80. Can't see him going for that.

 

There's also the Polaris Phoenix 200 too. Its cvt auto with reverse that is a little larger than the 90 and 150cc machines, looks like this https://carbondale.craigslist.org/sn...548174190.html

 

Both my kids started out on a Yamaha moto 4-200 at the age of 8 they have reverse and they do great on them and you can pick them up cheap for about $500 and their bullet proof machines. mine are 1986 models and they always start on the first pull or if the battery is charged up they fire right up. Or you can find an old 225 they have a low range and reverse also. I have $300 into both of mine and they are in perfect shape. Everyone thinks they are worthless because they are old slow and 2wd. And everyone wants the automatic so they don't have to teach their kids how to shift.