I do have something in common with Hailwood, i've lost my hair and i love chips! i can tell you that CV carbs can be a problem, in particular if you dont very lightly rub the inner piston cap with scotchbrite and wd40 to get rid of the light corrosion,also on the carbs for a bike like the Honda 500T their is a small spacer ring that holds the needle higher or lower depending on its thickness many people dont know that this ring should be in the carb cap because its been left out for years hence the rich running of the engine,regarding my mk11 Amals i think that the pin holding the float has moved to one side and allowed the float valve to come adrift thus letting the petrol flood out,i will sort it this weekend,i hope!!!