You can easily verify the problem by removing the float bowl, putting a cup under the carburetor, and turning on the fuel. If it just drips out from the needle-and-seat, rather than running in a decent stream, you have a blockage. Once you know that, you can satisfy yourself about the source by eliminating one component at a time until you find one that makes a big difference. Depending on the type of filter, it may be that, or it may be a chunk of crud that moves around in the hose. Whatever it is, once you've made the flow test, it is pretty easy to identify it specifically.
