That stock Offy linkage makes it a pain I think to equalize the carbs. In my experience it is too sloopy, especially when you have two different style carbs where the accelerator arms don't line up exactly. Plus the bolt connections slip. I would spend some time adjusting the linkage and maybe use a system like has been shown in the posts to you. The other issue I see is that the return spring for your accelerator arm is supposed to attach to a clip mounted on an oil pan blot. That gives it vertical action. Maybe that spring is weak too. Just my 2 cents.
