I found this little trick from Chris Speakman on the Honda Twins group

Actuall Fuel height can be seen , screw a plastic pipe into
the float bowl drain plug hole , around 1/4 inch below the float bowl
gasket should be ah right , see the carb pictures on my bike web page
http://www.geocitie s.com/teleman218 / make sure idle jets are clear , not partially blocked .

The pic is about halfway down the page.