Hi Malcolm, Sorry for the late reply. The Jikov was the older type side float chamber as is correct for my 1976 634 model.My friend used a plastic domestic 1 1/2″ elbow with a piece of 1 1/2″ pipe glued into it and a K&N filter attached to it inside the airbox. He made the outlet of the airbox bigger and pushed the other end of the elbow through and used a carb rubber to go from the elbow to the Mikuni carb. I have the Jikov hooked to the K&N filter now. It runs really well.