Eschew eBay and go straight to an authorized dealer or manufacturer or equipment supplier for new, alcohol-resistant rebuild kits that stand up to ethanol.
Install adjustable jets into the carburetor body carefully lest you damage the jet and body. Set the “turns out” to the manual’s specs, and then adjust idle speed to just avoid sputter.
Many carburetors have “Welch plugs” (aluminum core plugs) that conceal tiny, easily clogged holes. Clean thoroughly inside, and then install new Welch plugs.
If idle problems persist following a carburetor rebuild, check for air leaks by the intake manifold gaskets and mounting bolts.