A lot of interesting ideas and conversation. I currently own a KTM500EXC uncorked, too fast for riding with children. I am currently looking for a 2005 to 2007 CR250 which when jetted properly can fit that purpose. I would suggest a YZ250 less than 5 years old they are all the same. They are carburated, easy to start and amazingly light which makes it easier for you to stop, get off, and help the kids without wearing yourself out. When you open up the YZ it will run down most any bike and has amazing suspension. Just my 2 bits worth.