Here are some tips and photos from recent carburetor battles.
Best friend when dumping your tank, or filling from those gas cans you've had around for a couple years. Take a look inside. Gross huh? Get the common paper coffee filters, fold them like they showed you in high school chemistry (you weren't sleeping were you) and put 'em in the funnel you're using. Want this junk going into your carbs?
When using a paper element fuel line filter, I ran most of the tank through one of these filters, and it didn't catch anything noticeable.
The best tool for freeing up stuck float needles seems to be this little guy.
In case you don't recognize it, it's a brass bristle.22 caliber bore brush. Should be able to find 'em any where shooting supplies are sold. I used it in the seats to clean the sides of the seat as that seemed to be where my needles were hanging up. I also used it on the needles to clean them up a little. This will leave scratches in the soft aluminum, and the brush can damage the rubber tip, so don't go crazy with it.
If you've got a California spec bike with the vapor canister (aka charcoal canister) and you're having problems you might want to check it. Mine had GREASE packed in the VENT fitting (yellow, on the right here). That allows air to escape the float bowls but traps the gas vapors. It's important this fitting NOT be blocked, as the bowls won't fill properly with it blocked off. If this guy is dripping fuel, fix the carbs. The floats are stuck down.
Here's a tool I wished I had a long time ago. I now give you “The Finger”.
Got it from AutoZone. It's basically a longer and skinner version of your own digits. Works great for reseating the intake boots in the airbox or onto the carbs. Supposedly good for radiator hoses too. Snap-On has one too, but I bet there's doesn't have the same fine Chindian quality of this one!?