You say you have cleaned the carbs out a few times, but I can't resist saying that it might possibly be that the needle valves have "gunked up" a bit after sitting for so long, and now are not working optimally with the floats?? Just a thought.
I would try a bit of Brasso on the end of a cotton bud to clean the needle valve seats.
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[color=#808080][size=9]Yes,.. I too know how to waste Time and Money,...