Also, the factory repair manuals are found via the Manuals Link at the top of the forum home page.
If you have a 550F or 74-76 550K with original carbs then check the choke butterflies to make sure they open and close in synch. Then you need to bench synch the slides so that they are all approximately the same height to start with. For the carbs on the bikes I listed (which will have 022A or 069A stamped on the #4 carb or the manifold near the #4 carb) use a small drill bit (I usually use 1/8" some like 1/16) and set the carb slides so that the bit slides in from the airbox side with minimal resistance. You will fine tune the slide synch later when the bike is running. If you have a 77-78 550K then it has PD type carbs (the top looks kind of like an old fashioned skeleton keyhole), the #2 slide height is fixed so use it as a reference point to set the height of the others.
The floats are leaking from where? The tube at the bottom of the bowl? That generally means you need to adjust the float since that is it's purpose. As the bowl fills with fuel the float rises pressing on a needle the blocks off the input hole the feed fuel to the carb. I like to clamp my carb rack to a vertical source so hook up an auxiliary fuel tank to test for leaks before I mount the carbs back on the bike.
