It is possible that the tip of the needle is worn or not seeting correctly, even though it sounds like you've set the fuel level to a normal level. It might be that some debris from the tank or from the inside of the fuel line might have worked its way down to partially block the seat of the needle, or (I actually have this problem on one of the carbs on my R100/7) there is a worn spot on the needle that causes it to sometimes bind and not smoothly push up when the float level rises. Another possibility is the metal "bridge" between the float arms is slightly askew or binding on its hinge post. And, sometimes one just has to *CAREFULLY* bend up the tab on the bridge that pushes up on the float needle - BUT I'd do this only after determining it isn't any of the previous things, and ideally it should be done with the carb off the bike and WITHOUT putting pressure on the hinge pin (Easily bent/distorted and that creates more problems)..
Heck, I am starting to sound like the snowbum now - must be I AM getting older....
Also, along with new or old floats - do you have the original style yellowish white ones that are tied to a single beam, or the independent (black floats inserted on their own vertical posts) kit?
