1980 CB750f air leak

[braapbraap214]

I have a 1980 CB750f and it has a vacuum leak where the rod comes through the carb to hold the butterfly valves. there are felt seals there tht have been destroyed. ive been trying to get orings to work but cant seem to find the right size. has anyone had this issue and corrected it?   The problem with the bike is it idles up high when it warms up. thanks in advance for any help!

[seestheday]

Sorry, I have never heard of that failing.  Pics?