I have a boy that is getting a bit big for his CRF 50, and is already over-riding it. It seems natural that we move to a better and slightly bigger bike. A 65 is too much, and the whole clutch thing would be too much. The 4-stroke 70's don't have the suspension and such to make them worth looking at. So it seems natural that we go to the hopped up version of the KTM. He sat on a Pro Junior and it seemed too small for him. My big questions is this: What are the differences between the Pro Junior and Pro Senior. I am assuming that the Pro Senior is taller –*but can not find accurate specs that prove this to me. Other questions: Between 2004 and 2008 or 2009 what are the key differences between the model years? To me, it looks like the same bike, spec'd the same way. Jack is 7 -- and is big and athletic for his age. Can anyone out there help me? I want one of these that is a taller version Is this a good deal: http://portland.craigslist.org/grg/mcy/2180228052.html Thanks so much for your help.