[dhgeyer]

If the fuel filter is transparent, I'd inspect that as a very first step, and replace it if in any doubt. If I couldn't inspect it, I'd replace it just as a matter of course with those symptoms. I think that should be one of the first things you do, rather than one of the last.

Starting the bike for a few minutes won't really keep the carb from gumming up, at least that never worked for me. I'd lay my hands on some Chevron Techron (auto parts stores) and put in the appropriate amount and run a couple of tankfuls that way.

These things aren't a cure all, and you might well have some other problem. But, these are easy, and for me they have never failed to cure the kind of problems you describe, so that's where I'd start.