The circled plug in the photo below appears to be lead or some other soft metal and I believe it is recommended to be removed in one of the rebuild instruction steps. That is probably where the rubber plug would go. It's about the right size and it's the "idle port rivet plug" mention in step 13 on page 8 of "Mike's Carburetor Parts" manual for the Carter YF.
Last edited by MickeyP; 05/22/202512:19 AM.
1956 3100 three speed 6 cyl. Stock with a few upgrades.
