Quit posting pics of that MR50! It reminds me of a Christmas morning in 1978 when my brothers and I were lucky enough to walk downstairs to see a Honda MR50 and a Yamaha GT80 sitting in the entryway by our front door.
My brothers and I spent the next ten years riding dirtbikes with Pop; memories I cherish to this day.
Your dirtbike progression looks similar to mine:
'75 Honda MR50
'75 Yamaha GT80
'80 Honda XR80
'80 Honda CR80
'74 Honda ATC 90
'81 Honda ATC 200S
'81 Honda ATC 200X
'82 Suzuki RM125
'76 Honda CR125 Elsinore
'83 Suzuki RM250 (Still own it, and it's mint. Been a few years since I've ridden it, though)
Thanks for the pics.
Jim