The factory YZ623 ccm twin cylinder racer developed from the 1969 AS1 based model up to the latest 0W15 twin in 1975.

The 2 pictures from the early 1969-1970 version show clearly the combination of standard parts and factory specials, like the wheels/hubs. (You can "click" picture 2#-3#-4#).

Yamaha YZ623, 125 ccm 1969-1970