If you search the forum there are some good discussions on the process. Basically with the machine on the center stand you attach a pice of hose to the drain port of the carburetor in question. Bending the tube to run up the side of the carburetor and open the bowl drain valve. The level of the fuel in the tube should be even with the mating flanges where the carburetor bowl attaches to the carburetor body +/- 3 mm I believe. Yamaha says this should be done while the engine is running but I’ve never had to go that far to archive results. To high and the carburetor will overflow into the air box, to low and you will have a lean condition under acceleration. If the levels are incorrect the adjustment is made by slightly ( a little goes a long way here) bending the tab where the needle valve contacts on the float assembly. This process can also be done with the carbs off of the machine. A couple of old carb boots attached to a 2x4 and leveled works well. I have seen replacement needle valves have different lengths and cause problems and require big changes to the float flange. So if someone has been in your carbs and used non Mirkuni parts it could explain you always wet side. Another test you should do is with the carbs off, dry and up right blow into the fuel inlet, air should pass freely. Turn the assembly upside down and blow thru the fuel inlet. If you hear air moving you know you have a float level/ leaking needle valve.
