This is the Z50 Magnum bike. A 1969 Honda Z50A frame that was in such bad shape the guy I got it from (local legend "Minibike George") refused payment. The frame was stretched 2" in height, and 4" in length. A 124cc 4 valve engine with 5 speed tranny, Honda NSR50 forks, Fox float shock under the seat makes this hardtail a bit softer. Built in 2012.
On Pipeburn.com: http://www.pipeburn.com/home/2013/08/19/honda-z50a-50-magnum.html
The build thread: ...50 MAGNUM Build. 1969 Z50 K1 big frame.