Get yourself a couple of cans of carb and choke cleaner (I prefer STP in the aerosol can) and spray all the chunks off to start. Clean out the bores with cleaner and some Q-tips. Open up the fuel bowl and make sure there isnt any junk stuck on there. Pull out the needles and clean them. Make sure there isnt anything stuck in the needle bores. Be careful not to get too much cleaner on the fuel bowl gasket, or it will balloon up for a day before you can re-install it. It is made to expand when it comes into contact with liquids. oke
You have the hard part done now. Blow everything out with compressed air, and reverse the process till everything is back together. Dont over tighten the fuel bowl screws or strip them out. Mine are phillips, and are fairly soft. I would say leave the 4 carbs bolted together though, it is a pain to get them aligned just right again.