I will try those suggestions. Now that I have two carburetors I'm a little less skittish about ruining one ;)
I'll try running with the choke on but if everything is stock I shouldn't need to rejet though, right? I worry if I rejet I might just be band-aiding some other issue, like an air leak... Admittedly, I reused the old gasket for the new carburetor.
I'll get back in a few hours but still open to suggestions so I can try 'em all at once. Thanks!(edited)