How do I adjust the floats?
You can use a standard tape measure (in mm). Float height is measured from the rim of the carb body to the bottom of the float with the float valve *just* seated, i.e... the spring on the float valve is not compressed. You'll have to hold the carburetor sideways to keep the weight of the float itself from compressing the spring. Bend the tab to get to the correct float height. Float height is 17mm +- 2mm, but make sure to check your Service Supplement for your year.
Theory: Each set of carbs has a different recommended height (listed in the service manual for the given bike). If the floats hang too low, your bike can (and most likely will) run lean, and if they sit too high, you'll likely be fighting a rich running bike. A 6" ruler or a basic set of calipers can be used to measure the height. To measure, you want the floats to just be touching the fuel needle (which has a spring on it; you don't want to compress that). To adjust up or down, you just bend the small metal tang that rests on the fuel needle.