Non US Oceania, Canadian and Euro Custom BS34's didn't have the plug over the Pilot scew.................. The reason for this is the US models were EPA mandated and set at the factory and so were the needles, (non adjustable). That way mechanics couldn't access the pilot screw and change EPA mandated settings
Pilot screws weren't shown on the parts diagram and had no part no for reference. en=ven if someone wanted to.
In amongst the parts manuals on the net there is one for the japanese 80/81 4E3 Standard and this parts diagram shows the Pilot screw and seals/ring/spring and a part no.
No after market supplier has copied the pilot screw for aftermarket sales. With the part no i found on the 4E3 diagram 5twins did a search and found a substitute pilot screw that is used on another BS34 carb and he bought it and compared it with the Xs650 Pilot screw. The dimensions are the same.
So no, the Canadian, Oceania and Euro BS34's did not have the cap over the pilot screw