5/8" aluminum expansion plug Fits many types of carburetors. Remove this plug to clean out the choke piston well. Place the new plug into the hole. Hit the middle with a drift punch, which will cause the plug to expand and fit tightly in the hole.
2100, AFB, RBS choke clean out hole plug.
Also fits the 4 Jet choke piston clean out.
Autolite 4100 - fits choke piston clean out hole 5/8".